[voxic11]

I have paid for YouTube Premium for years and watch YouTube nearly every day and I have never seen an ad from YouTube (you still may see baked-in ads from the video creator but those can be automatically skipped with the SponsorBlock extension).

[Gareth321]

The ads which the "ad free" Premium service permits:

1. Sponsored in-video ads.

2. Ad overlays on videos (at the discretion of content creators).

3. Merchandise store ads below videos (also at the discretion of content creators).

4. YouTube and Google ads for various products and services in the video feed.

[voxic11]

Ah I also use uBlock Origin so I guess that is why I haven't seen #4.