YT premium comes with their own version of sponsor block, but you manually have to hit the skip button.
But I don't hold youtube accountable for what creators decide to put in their videos. I would grind my axe with the creator instead, it's their video and their choice. Youtube gets no cut from those segments.
The fact you hold them acountable or not is one thing. Calling it ad-free is another.
As a paid YouTube subscriber, I’ve always wondered if that skip was only for us. It would be kind of bullshit if it was also for ad-based free viewers too as it would imply that google is free to show you ads they make hard to skip but they make it easy to skip embedded promotions and stuff.
This has been a life saver:
https://addons.mozilla.org/en-US/firefox/addon/sponsorblock/
Crowd sourced in-video sponsor auto skip, I have been contributing to it myself as the UX is great.