My only concern is the speed of my upward mobility (which other companies couldn't have provided, even with pay increases), and I'm a bit concerned about the potential consequences of mass layoffs if an economic downturn takes place.

I don't want to be the first one out because I have the shortest time in the company. My higher pay won't mean shit if the labor shortage, which I doubt is even a real shortage and is just wages rising too slowly, turn around and becomes a labor surplus because entire industries are closing.