can't compare directly, as the leveling system has changed. bg1 time had exp penalties for multiclass, and bonus levels for drow, etc. that kind of stuff.
I don't think tabletop to crpg compares well either. as tablettop has tons of action that is rp, and noncombat. crpgs tend to focus way more on combat, thus character building is a bigger element. yeah, you can spend years at one level.. becuase you have entire sessions of shopping, talking, etc.
this likely will push power towards martials. low level=limited spell slots. cprg in general means limited spell lists.
labeling it BG 3 doesn't help with this. as noted, you kindof expect that progression. to go back to a smaller, more grounded level, for 3 is odd. Then on top of that, the level range expected for mindflayers/gith.. A single, regular ass mindflayer is CR 7.
A wizard gets one 6th level spell at 11.
like I said about wrath of the righteous, its insane build depth makes it one of the best crpgs in history. if you are throwing CR into the trash and just having players start at 1, regardless of foes or backstories, I think its better to just go full build depth and give full level 1-20 access. (kingmaker was a bit silly starting the characters at level 1. they should have started at level 3)
there is another option here, which again goes back to WotR. secondary progression/feats/level ups. Mythic paths. you could have your 1-12 class levels, then another 1-12 "Mythic" progression, that is separate and unique to the game/setting. in Wotr, its outsider/alignment based. but doesn't have to be. the "mythic paths" could be mage guild, theives guild, slayers guild, werewolf, vampire, aboleth path, hivemind path, blessings of shar, blessings of elune, etc. A secondary leveling system, to allow deeper character builds.
of course, afaik theres nothing like this. just saying a system like this could justify a lower class level.
