Apparently a lot of the lawyers filing bogus lawsuits for Trump are worried they could lose their licenses to practice law if they commit outright fraud. (Knowingly filing a fraudulent lawsuit is fraud on the part of the lawyer! Who knew?)
So they are being very careful in what they claim. For example one suit complained about the vote counting room being very loud, as if counters were counting in their heads and could lose track because of noise. Another suit complained about the presence near the poll watcher of "a large intimidating man". All real complaints (not fraud), but not anything you could sue over.
I think this is the reason why they keep on getting dismissed: They are designed to get dismissed without any lawyers getting sanctioned! So Trump's "legal defense" is just as much a fantasy as his claims he won.