This is pretty much correct. To this day, pretty much every region has their own ruleset. The main issues are Meta Knight, stagelists, and certain rulings such as ledge grabs.
However, although there are certain projects that investigate items in competitive play, the generally accepted consensus is to turn off items, which was directly taken over from Melee.
The original recommended base ruleset was created by the members of the Melee Backroom on SWF, which took the Melee ruleset and changed it a bit to fit Brawl's gameplay. The original "no items" rule was made because once you turned on items in Melee, you would get container items (capsules, crates, etc.), out of which some would explode with Bob-Omb explosions. It was universally agreed to not use items at all because of that.
Brawl does have the option to turn off the containers, but play with items that aren't broken never was further pursued, side for the items that characters can spawn (Peach, Diddy), and a few little side events to test stuff for an item list.
Back when that last EVO happened, a lot of things occurred that caused the hosters of it to stop picking Smash back up. The backlash from Smash players regarding the item ruling is only one thing. Granted, though, the EVO people had been contacted by the BBR representation, but the recommendations had been ignored.
There was also drama involving the high level players if I recall correctly. It's so long ago, my details are a bit woozy regarding that, and that was only shortly after or before my admission to the Brawl Backroom on SWF.
