In my experience, it has been smooth in the past.

FYI atom project is dead. There is a community form available but it was to buggy for me.

If the advertisers start paying less, then Google will just increase the number of ads shown to the user. And playing content on more tabs won’t even matter to them.

The issue is that they are a monopoly so they control and they can do whatever they want. The alternative is federated video services but those aren’t matured yet.