[kosciusko51]

I’m not upset with anyone flying first class, but I want to know why the seats are getting smaller and the rows keep getting closer in coach.

[circlecity]

"but I want to know why the seats are getting smaller and the rows keep getting closer in coach."

$$$$$$$$$

[Blue Jays]

If airlines can configure seating to get even SIX more passengers into the aircraft, they make that much more on each packed flight.
Eventually passengers will determine the aircraft used by Company A is far more comfortable than the very cramped aircraft used by Company B.
People then begin to book flights on more comfortable Airline A if prices are somewhat similar.
It gets to a point that Airline B simply will not be able to lower their prices enough to address the discomfort and that is "the magic point" when accommodations start to get improved again.

[TexasGunLover]

why the seats are getting smaller and the rows keep getting closer in coach

Higher density means more profitable flights.

[DoodleDawg]

I’m not upset with anyone flying first class, but I want to know why the seats are getting smaller and the rows keep getting closer in coach.

If the airlines do not deliberately make flying coach as uncomfortable as possible then how can they get you to pay more for premium seats?