I think it's very much a case of a certain group seems to think their views are the "silent majority" and are exceptionally vocal about it, when in reality the advertisers know that they are really very much a vocal minority.
If the "alt right" etc were anything like as big and popular as they seem to think they are, the advertisers would generally flock to them, the reality is that they're not and for many brands that try to be as "widespread" in appeal as popular they're toxic because those brands know their customer base to a very good degree.
I saw a clip of a school board meeting from the US the other day that summed it up very nicely, one of the parents from that district made the point that she and most of her ilk don't have the time to go to every school board meeting and spend the time campaigning, whilst the "anti woke" book banners are exceptionally vocal and are making it pretty much their entire lives (IIRC it turns out that across multiple states the requests for banning loads of books are coming from what is often a very small number of people, many of whom are taking advantage of the fact the book "review" laws don't usually require you have to be a parent or person in the district, or even the state, let alone actually have looked at the book and know what is in it).
Advertisers and companies tend to be fairly flexible morally, they don't usually care about the ideology of people, except where it actively hurts them or their carefully cultivate image to have their products shown next to say someone talking about how slavery wasn't bad, or that the globalists should be "dealt with" etc.
Basically the pressure the advertisers put on the platforms is pretty much "just don't make us look terrible" or "don't cause us to have to issue an apology to a signifcant part of of customer base" (or "don't put us next to flat out illegal content").