>>79738202TV anime production has limited time, money and personnel. It is simply impossible to maintain animation like
https://sakuga.yshi.org/post/show/8714/ all the time, even for a top-tier studio like Kyoto Animation. It's not that they can't do it, it's that there is no time. Six episodes of animation already hits the upper limit of running time for animated movies (120 minutes), which usually aren't even that long. And yet there is less production time than in a movie, and you still have 6 - 18 episodes left to go.
This idea that there's a few seconds or minutes of great animation surrounded by still images and mouth flaps is, again, a myth. Maybe you can find episodes where production was really messed up and something like that ended up happening, but there's nothing normal about that.
And when all is said and done, anime still looks radically better than American shows. It's possible that American shows have more frames of animation, but that doesn't mean they're good frames of animation or that simply having animation means anything.