What's the point in making cheap breakable junk that is cheaper to buy?

You seem to be confused as to what 3d printers are for. They're not going to outperform mass-production injection molded for price. If it is something you can readily buy, it's not something that you should be 3d printing.

3d printing is for making things that are not commercially available: hard to find parts, custom parts, prototypes.

What's the point in a home-ink jet printer if the quality is so much less than the quality of National Geographic?

Because sometimes, you want to print something besides a 1:1 copy of something from the newsstand. Likewise, it would be cost-prohibitive (not to mention retarded) to contract someone to spin up a photogravure press so you could make a pristine copy of a utility bill for your filing cabinet.

Manage expectations.

What's the point in making cheap breakable junk that is cheaper to buy?

You seem to be confused as to what 3d printers are for. They're not going to outperform mass-production injection molded for price. If it is something you can readily buy, it's not something that you should be 3d printing.

3d printing is for making things that are not commercially available: hard to find parts, custom parts, prototypes.

What's the point in a home-ink jet printer if the quality is so much less than the quality of National Geographic?

Because sometimes, you want to print something besides a 1:1 copy of something from the newsstand. Likewise, it would be cost-prohibitive (not to mention retarded) to contract someone to spin up a photogravure press so you could make a pristine copy of a utility bill for your filing cabinet.