Yet again, I am not arguing that the things I wrote in this post are true, I was simply brainstorming ideas as to why this does not exist and giving a suggestion on a possible solution to the issue, given the recent event in which multiple groups decided to leave MangaDex surrounding the issues of site traffic and money
In the forum post made by the groups leaving MangaDex stating their problems with this site they noted that they felt MangaDex was forcing them into using its reader, and intentionally making their sites obsolete. It is fairly obvious, regardless of what anyone thinks that MangaDex WILL REDUCE TRAFFIC TO THEIR SITES for better or for worse and this will definitely have an effect on donations and ad revenue for these groups. And while I am aware that groups can put a donation/patreon link on the group pages, I would not expect a casual reader of manga to frequently search for and encounter that page. I barely look at the group pages myself, as I would consider myself a part of that more casual group of readers.
I implied the idea of a donation button for groups in a more obvious place of the site (such as in the manga reader itself) as a way for MangaDex to show to these groups, whose perspective is that they have been unfairly treated by MangaDex and its staff that the sites purpose is not to drive them and their sites into irrelevancy or otherwise making them obsolete.
Fundamentally MangaDex, as a site that not only acts a a platform for discussing about manga but also hosts said manga and a variety of other content does strip away a degree of these groups independence, and I can see why this would be scary for them. I suggested this idea not just for the groups to help maintain what is effectively a hobby but also as a way for MangaDex to show that it does listen to groups and does not want to make them obsolete, but rather to make a site in which manga can be read, shared, and discussed about freely by those interested in it.