True, but for bitchute you can automate most of it. I use youtube-dl to download videos from sites, and ffmpeg (ffmpeg -i source-video.mp4 -vf "select=eq(n\,0)" -q:v 3 thumbnail.jpg) to get the thumbnail for the video (that command just extracts the first frame).

I could probably script that so that I can just give it an URL and it downloads the video and gives me a thumbnail with one command, but I don't upload that frequently that it's necessary