While using YouTube app, the feed floods down by videos which are actually AI output. Not just the animation or just audio. There are videos fully made of artificial tools. Missing the old and classic human contents which enrich the mind. Is there any way to get rid off this problem? Anything like algorithms modifier?

Turn off your watch history, don't use the YouTube app at all, use a web browser instead, and always start your browsing on https://www.youtube.com/feed/subscriptions which only shows your subscriptions rather than random other things. To the extent that suggestions still show up alongside videos you watch, uBlock Origin rules can help hide those so you can remember to stick to only the channels you've subscribed to.

Alternatively, YouTube channels have RSS feeds, which only contain the videos from that channel, so using those in a feed reader could help.

Stop using YouTube?

Agree. Im annoyed by ai generated thumbnails. I dont click these videos. Its a clear sign for for low quality content