Its an unwritten rule
Jones made him look like reindeer in lights and was all over him in championship rounds while Reyes was gassed and just tried to survive. If there was no time limit Jones wouldve eaten him alive sooner or later. Even if Reyes outpointed him with one or two barely significant jabs during early rounds which were merely just ant bites compared to the takedowns and kicks Jones threw later in the fight that possibly destroyed his ACL which his reaction kinda gives away in the Ariel Show. That its not enough to dehtrone someone like Jones and Reyes needs go back to drawing board after healing up and work on finishing moves if the rematch presents itself one day.
If there was no times limit Jones would have won? ok sure maybe but as I said, fantasy rules don't matter.
Reyes didn't land many jabs, not sure what you're on about. Strikes that land are equal to takedowns that he instantly gets up from, you must be one of the judges.
Its totally different story when challanger wins last 3 rounds in row.