PBS Space Time started doing it. Along with some clickbait/pull titles. I stopped watching.
Check out the DeArrow extension. Crowd sourced thumbnails and titles. It's great.
This is like removing the warning signs from toxic material containers.
It's not though. Even generally good YouTubers are forced to play the thumbnail game. Garbage content is typically revealed in the community title.
Nobody is forced to use them. If they really want an audience swayed by arrows, I don't want to be part of their audience.
I don't want to hide the arrow. I WANT to know what channels to avoid just by looking at the thumbnail. It's a feature, not a bug.
You can configure it to not be enabled by default, but you click a little blue circle next to the title and it will show you the community version.
Plenty of good content is forced to play the clickbait thumbnail/title game and it would be a shame to miss some of it because of YouTube's incentive problems.
That's actually pretty damned good.
For channels I already subbed to, I forgive that if the quality remains consistent. PBS Space Time's videos have remained stellar, as always.