The 'SponsorBlock' browser plugin helps a lot to shorten these long videos by skipping sponsored sections, intros, promotions, credits, etc. 'uBlock Origin' also helps by removing the ads.

For avoiding channels that are effectively spam, 'Channel Blocker' is helpful by adding an 'x' button you can click to block videos from that channel from being displayed. Another one, 'BlockTube' is good too which lets you auto-block videos based on keywords in video titles.