Promotion is baked into so many videos on youtube - just as it has been in television and film for decades. I'm not sure whether it's getting worse, or if it has always been this bad and I just didn't notice it as much.
Even better are ad sections that are coloured differently to that of the main video. A good example here is Chain Bear [0]. Chain Bear's colour style is based around yellow, and here the sponsored section is NordVPN, with a blue colour scheme. Very easy to skip exactly to where the content starts.