I use ad blockers and open source privacy focused software whenever I can but occasionally I have to use computers that don’t belong to me or an older phone where my usual applications aren’t installed and seeing all the advertisements just feels dirty and dystopian.
I think the worst ads are the text to speech ones that say “Download this app today”. The unblinking energenic people saying you can make a living at home are probably a close second.
I signed up to Vessel [1] when they were giving out the 1 year free trial, and it was only 9 months or so in that I realised that it had ads. It was kinda jarring, especially for a paid (not that I did) service.
[1] https://en.m.wikipedia.org/wiki/Vessel_(website)