I'm failing to find any ads at all on their site. I tried to follow every possible path from getpaint.net to a download and couldn't find a single ad (ublock etc. disabled ofc). Takes more clicks than really necessary, but I don't see any way to download the wrong thing.

The only thing "objectionable" (scare quotes intended) is that the version available on the Microsoft store is paid even though the software is freely available. I believe they aren't even allowed to reference the fact that it's free elsewhere on the MS store page. Certainly a weird situation, but not something I'd lose sleep over either tbh.

Edit: Oh, and of course certain cites (e.g. chip.de) out-SEO the real site to peddle their own version of it. And, who would have thought, Windows Defender immediately barks that the chip.de version is trojan-riddled...

I don't see any misleading links at all. It takes more clicks than it should to actually get to the download, but there was nothing malicious on any of the pages.