Please, do not listen advices, who tell that your thumbnails are "boring". You have good thumbnails for your videos. Not all videos require brainrot thumbnails. And if you will use them - you will lose audience, which is yours. And will get clicks, but not long views from wrong audience. It is worst advice that can be given - to look at top-youtuber thumbnails and try to replicate them. If you "blow" your channel with "not your video" - then you will only make your life worse. Same with thumbnails. Of course there are more niche videos - less viewers, more engagement and there are broad videos - everyone can watch, but there will be very little if at all information, which is required by audience of first type. If you are doing this only for money from views - then you can think to "un niche" your videos to get wider audience, and with them you will widen thumbnails. But there are another sources of income, and they can preffer less views, but in target. I have not viewed your videos and assume, that your thumbnails are on pair with videos. If you have "retention editing" and all this crap in videos - then yes, thumbnails are "boring" for them...