Since the Umbraco 16 release, Umbraco ships only with the TipTap Rich Text Editor. This was unfortunately something that Umbraco was forced to do. TinyMce 7 has a license that is incompatible with the open source license of Umbraco and TinyMce 6 was going out of support.
Source: [Dev.to](https://dev.to/luukpeters/tiptap-is-not-broken-your-expectations-are-5h8m)