1v1 tournament is super cool how it gives a completely equal playing ground, as is, but agreed that it does make maxed builds pretty accessible to try out. Having said that, being able to demo the various maxed F2P builds at diff level points before committing the hundreds of hours to make one has made it really nice to figure out which are most fun to play.
I really like the level bracket idea, whether that be X0-X9 ranges or specific reserved levels like 33, 55, 63, etc.
One thing that might help is separating tournaments into different “rulesets” or “formats,” similar to other competitive games.
For example:
* Mirror Format (what currently is the system. where everyone uses preset equal builds they dont have to make):
Both players are forced onto the exact same preset build/loadout. Pure skill matchup. Great for fairness and accessibility. But should require a 250k/1mil gp donation to start, or admin invocation to make less common.
* Open Format:
Anything goes within the combat level bracket. Players use their real builds. preserves account identity, economy interaction, and the prestige of unique builds.
Could also have an admin be able to set automated weekly schedules for the various tournies and their brackets/formats.
Example:
Tues/Thurs/Sat 12:00 UTC:
Lvl 33 Anything Goes [player builds]
This is prob a massiv amount of dev time but if the sky was the limit I made some AI slop loose concept to try to capture what the typical player facing ui could resemble. (The admins wud have their own special screen display and way of being able to set a daily/weekly scheduled format)

Adding duos/trios/battle royale wud prob be a nightmare to fully implement, but could fit in the same system potentially.
tldr: I think having multiple levels of configurability is probably the sweet spot because it preserves both:
mirror preset builds gives fair equalized competition and also lets peeps demo out builds before building them on their own
But for open format, the excitement/prestige of actually building unique accounts in the real game/economy is maintained