I have noticed significantly less interesting content on YouTube over the past 2 years, but I attribute most of it to a lack of small creators on the platform now. It takes a ton of time and effort to even make a good 10 minute video. This is a big time commitment on top of your other job, family, etc.
10 years ago there were no professional outfits on YouTube. Then everyone started to "grow up". About 5 years ago people started seeing there was money to be made on YouTube, so a ton of new creators joined the platform and there was tons of content. Fast forward to now and creators have realized it's actually very hard to live off YouTube, so a lot of them have moved on.
If all they want to do is show off their project they now turn to Instagram and/or TikTok. If all you are after is likes (and don't care about monetization) it is actually way easier on those platforms (due to their discovery engines) with a fraction of the production time.
I think YouTube knows this (hence shorts). The general rule of thought around YouTube now is to grow your brand using shorts and then monetize it using long form videos. So unless a creator has a large enough following to support their work making long form videos (over 90s) there is really no incentive anymore.