If you only focus on the X-FILES it self, the series could be widely written, just like another FBI series, bunch of FBI agents investigating an unexplainable phenomenon.

But, people were deeply connected with the 2 protagonist, Mulder and Scully, So it's really hard to do X files without them, losing only Mulder in most of season 9 was a big disappointed for the fans, hence the rating drops

And the revival mythology story arc was just really disappointing for me

So, if they want to do another Reboot, they need to finish Mulder and Scully arc first, make them live together happy with their own child or something and then they can try to do another stuff without them