Crunchyroll is skating very close to this line.

For paid accounts they don't show ads during an episode, but they're injecting their own little things before some episodes.

My policy now is that every time they do this, I suspend my membership for 2 months. So basically I pay them for 4 months of the year.

That lets me binge each complete season of anime, while still punishing their misbehavior.

It's trivial for them, but it feels like a small win for justice for me.