If a 13yo boy watched TNG in the 90s and found it entertaining, why is it assumed a 13yo boy in 2026 would just absolutely hate it?

I think this assumption started as something reasonable and morphed into something that really isn't. Episodic TV works just as well now as it always did, but there's much much more competition for a potential viewers' time now than there was in the 90s. Making it more serialized is a viewer retention strategy.

Viewer watches a couple episodes of an episodic show. Comes back if they want more of the same.
Viewer watches a couple of episodes of a serialized show. If you managed to hook them with a mystery box or whatever they keep coming back to see what happens next.

Instead of every episode increasing the chance a viewer burns out, it increases the chance they become too invested to walk away.

Compare TNG vs. DS9. The Dominion war and ongoing politics provided a level of, "what's going to happen next week," that TNG never had with the exception of some specific multi-episode stories. After a focus on serial plot threads, I think really was a natural evolution. It's a tiny step from execs thinking of it as a retention bonus to thinking it's a retention requirement. Then, if the focus of your show becomes the serialized plot thread, the episodic content starts to get viewed as filler. It might be entertaining but it gets in the way of the next anticipated story beat. Take too long and the people who are only there to see what happens next give up. Trim that part down and it's obvious you don't need 24 eps to tell the story anymore.

tl;dr: It's not a question of age of the media. Or even the quality. It's the format. Continuing plot threads is a way to keep people invested in a crowded media landscape.

If a 13yo boy watched TNG in the 90s and found it entertaining, why is it assumed a 13yo boy in 2026 would just absolutely hate it?

I think this assumption started as something reasonable and morphed into something that really isn't. Episodic TV works just as well now as it always did, but there's much much more competition for a potential viewers' time now than there was in the 90s. Making it more serialized is a viewer retention strategy.

Viewer watches a couple episodes of an episodic show. Comes back if they want more of the same.
Viewer watches a couple of episodes of a serialized show. If you managed to hook them with a mystery box or whatever they keep coming back to see what happens next.

Instead of every episode increasing the chance a viewer burns out, it increases the chance they become too invested to walk away.

Compare TNG vs. DS9. The Dominion war and ongoing politics provided a level of, "what's going to happen next week," that TNG never had with the exception of some specific multi-episode stories. After a focus on serial plot threads, I think really was a natural evolution. It's a tiny step from execs thinking of it as a retention bonus to thinking it's a retention requirement. Then, if the focus of your show becomes the serialized plot thread, the episodic content starts to get viewed as filler. It might be entertaining but it gets in the way of the next anticipated story beat. Trim that part down and it's obvious you don't need 24 eps to tell the story anymore.

tl;dr: It's not a question of age of the media. Or even the quality. It's the format. Continuing plot threads is a way to keep people invested in a crowded media landscape.

If a 13yo boy watched TNG in the 90s and found it entertaining, why is it assumed a 13yo boy in 2026 would just absolutely hate it?

I think this assumption started as something reasonable and morphed into something that really isn't. Episodic TV works just as well now as it always did, but there's much much more competition for a potential viewers' time now than there was in the 90s. Making it more serialized is a viewer retention strategy.

Viewer watches a couple episodes of an episodic show. Comes back if they want more of the same.
Viewer watches a couple of episodes of a serialized show. If you managed to hook them with a mystery box or whatever they keep coming back to see what happens next.

Instead of every episode increasing the chance a viewer burns out, it increases the chance they become too invested to walk away.

Compare TNG vs. DS9. The Dominion war and ongoing politics provided a level of, "what's going to happen next week," that TNG never had with the exception of some specific multi-episode stories. After a focus on serial plot threads, I think really was a natural evolution. It's a tiny step from execs thinking of it as a retention bonus to thinking it's a retention requirement. Then, if the focus of your show becomes the serialized plot thread, the episodic content starts to get viewed as filler. It might be entertaining but it gets in the way of the next anticipated story beat. Trim that part down and it's obvious you don't need 24 eps to tell the story anymore.

tl;dr: I don't think it's the age of the media. It's the format. Continuing plot threads is a way to keep people invested in a crowded landscape.

If a 13yo boy watched TNG in the 90s and found it entertaining, why is it assumed a 13yo boy in 2026 would just absolutely hate it?

I think this assumption started as something reasonable and morphed into something that really isn't. Episodic TV works just as well now as it always did, but there's much much more competition for a potential viewers' time now than there was in the 90s. Making it more serialized is a viewer retention strategy.

Viewer watches a couple episodes of an episodic show. Comes back if they want more of the same.
Viewer watches a couple of episodes of a serialized show. If you managed to hook them with a mystery box or whatever they keep coming back to see what happens next.

Instead of every episode increasing the chance a viewer burns out, it increases the chance they become too invested to walk away.

Compare TNG vs. DS9. The Dominion war and ongoing politics provided a level of, "what's going to happen next week," that TNG never had with the exception of some specific multi-episode stories. After a focus on serial plot threads, I think really was a natural evolution. It's a tiny step from execs thinking of it as a retention bonus to thinking it's a retention requirement. Then, if the focus of your show becomes the serialized plot thread, the episodic content starts to get viewed as filler. It might be entertaining but it gets in the way of the next anticipated story beat. Trim that part down and it's obvious you don't need 24 eps to tell the story anymore.