Yes, this bothers me as well. I pay for YouTube premium but that does not skip the "native" ads that YouTube considers part of the content. Sometimes, it legitimately is something interesting as product like when LTT launched their screwdrivers (I decided they were too much for me, but were worth a look), but to hear about Better Help, Hello Fresh, Nord VPN, or Raid Shadow Legends again... it pisses me off.
YT isn't adding those sections, the creator is. Maybe instead of blaming YouTube, ask your favourite YouTuber to not add the sponsorship section?
And when they reply saying they need them to pay their bills, send them your reply of what business model they should instead adopt ?
How come YouTube is advertising to me but not giving back enough to the creator such that that creator then has to take sponsors to pay the bills? If YouTube's ad tech were good and the deals fair, the sponsors would just advertise on YouTube and the creators would get paid too. the fact this isn't happening means the process is failing, and it's certainly not my job nor my problem to fix it. Until they figure that shit out, I'm going to keep blocking both.
SponsorBlock skips those. The downside is the video sometimes needs to be a couple of hours old before someone gets around to adding the skip sections.
Google doesn't embed or control those adverts and doesn't benefit directly from them, and they might not want to anger the minority of their user base with this addon any more than they already are by forcing yet more unskippable ads on them.
If the seek bar was disabled while a "this video is sponsored by" segment started playing, I would just stop using YouTube immediately.