Paying to remove ads is part of the ad business model. Upset your customer enough until they give you money to make it stop. Once you pay to remove the ads you have rewarded them for implementing ads which lets them know that implementing ads was a great way at making money.
So YouTube premium is not another model. It is the same model. Another model is paying for a service that never had ads at all such as NebulaTV or CuriosityStream.