Is this an American thing? I have never seen ads in start menu in EU (Greece). Unless you mean some apps like Spotify which come with a fresh install, but I have uninstalled all of it.

I understand the rage with the start menu and, even though I am indifferent to the ui, I accept that mist people hate it. But what about onedrive? It seems to be one of the worst features for everyone, but I just have it disabled and only use it when I want to. Turn off all backup features, move it to another drive and disable auto start.