I think you've got it backwards.

That was the hallmark of old TV, on networks. Since the start of TV in the 50's.

There are tons of modern TV shows that don't do anything you're talking about because they're made for streamers or paid TV without ads.

It sounds like you watch different shows than I do, but I watch a lot of TV and haven't seen what you're talking about in many, many years. Not with Squid Game or Stranger Things on Netflix, or Andor on Disney+, or White Lotus on HBO, or Severance on Apple TV+, or even something like Alien: Earth currently on FX/Hulu.

You might want to find better places for watching TV...

This is mostly an issue for content produced to still be on regular tv and streaming, like on Paramount. Star Trek Discovery and Strange New Worlds, for example, are not as dramatic as described above but you can always spot where the adbreak would have been. Cut to black and a re-establishing shot at the least. These are modern shows like you describe but still the TV medium has some influence.

One thing I do notice more and appreciate from streaming (sense8 in particular) is that shows are more varied in their runtime. Episodes being 40 minutes to 75 in length just depending on the needs of the plot, not even finale related or anything

Also an issue with YouTube...