What I absolutely have issues with is targeted advertising, having to modify content to make it advertiser friendly (i.e. reasonable people on YouTube having to avoid swearing/use infuriating euphemisms for self harm or suicide etc in case it makes the video not advertiser friendly), and the frankly offensive and unjustifiable amount of tracking that goes along with it.
I wish we could ban dynamic advertising (can't think of a better term, as in targeted, tailored advertising that is aware of what it's being advertised against) and just allow static advertising.
I also wish it could be codified in law that what is shown to me on my computer is entirely up to me, and if I want to block advertising on my computer, that is my choice, in the same way I can make a cup of tea during the ad breaks in tv, and skip over the advert pages on the paper.