Don't understand why more companies don't just make ads opt-in as a trade for more features

A lot of people are ok with ad supported free tiers

(Also is it possible to do ads in a privacy respecting way or do people just object to ads across the board?)

I would object to ads across the board in this case (though I’m generally fine with even targeted ads). It would create a customer-client relationship between companies paying to advertise and the AI company, creating an incentive for Anthropic to manipulate the Claude service on their behalf. As an end user that seeks input from Claude on purchasing decisions, I do not want there to be any question as to whether or not it was subtly manipulated.