I think the developer should have just made the app ad-free, and charged for features people will want.
It's not a feature to remove ads. It's just normal. At least for many of us Linux users, we never see ads since we have so many ways to combat them.
But yes, if Lemmy starts to become very popular, it will pull in everyone who uses windows and has ads and shit in their face all day. They are used to it. Maybe they will pay.