I agree the process with google and apple is fickle and horrible. However,I did read the article you linked, since the social media app was using the mark "clubhouse" first, they would have legal priority. To win trademark infringement cases generally you need to prove there is confusion and priority.

If you happen to later get a trademark through an office, in most jurisdictions you don't get to "steal" those rights. They are quite straightforward to cancel, although it takes some time.

That said, Apple and Google's policies are fickle and confusing and indeed your best bet is to have connections to their companies. IMO google is worse because Apple has a group you talk to, and google has you submit forms to something they don't typically respond to.