the most financially sucessful Trek movie of them all
That would be Star Trek: The Motion Picture
There was a snippet in an early 80s "Starlog" where Paramount execs admitted to being surprised by the final box office returns of TMP. (It was still running in suburban cinemas in August 1980 in Australia, for example, earning small but reliable continued sales.)
Originally pronounced a flop because it had so much
outlay to recoup (and critics and fans tended to be critical of its slow pace), TMP eventually ended up with very respectable profits. Many fans went back every week, for many months. There was no TOS in prime time syndication from about September 1979 - Roddenberry suggested that Paramount withhold it to make fans really hungry for new ST.
But... so-called "sleeper hits" make studios very nervous. They'd rather make back the entirety of their investment in the opening weekend - ie. on multiple screens, and modern cineplexes make simultaneous coverage possible.