Whats the real reason that television has largely devolved into ~8-episode season hyper-expensive annual (or longer) mini-movies?

I'm know I'm not the only one who has become exhausted with the state of television. I grew up when television (outside of specific mini-series) was still 20-26 episode season affairs that had regular yearly schedules. As far as I can tell for scripted television the only types of shows that retain that are network sitcoms, likely because they can be made very cheaply.

That's where I'm getting confused too, what good does it do to have an 8 episode season where each episode costs around $15 million to make (The Boys for example) and can take over a year to come out when back in the late 80s a 26 episode season of Star Trek TNG cost about $2 million per episode ($5 million accounting for inflation).

Why has television ended up in this place?