In all honesty, I'm sorry to break it to you, but I honestly feel at this point that there just isn't ever going to be a game that doesn't have the EXP All mechanic baked in anymore. It's been nearly four years since the first Switch Pokemon game, Let's Go Pikachu and Eevee, and all of the mainline games on the Switch thus far have had the EXP All mechanic baked in and unable to be turned off, as even Legends: Arceus has it, and even the minor one-off remake BDSP did too. LGPE, Sword and Shield, and Legends: Arceus have all had it, and given this I think the permanent EXP All mechanic is here to stay in every mainline Pokemon game going forward.
Gen 9 likely isn't going to remove it in any of its games either. In other words, given we've had four different games that have permanent EXP Share over the span of four years, I think you should fully submit yourself to the expectation that it's going to be the norm from here on out. In other words, for Scarlet and Violet? Fully expect that baked-in, permanent EXP Share will continue to be in it. And the same goes for every mainline game that follows: whatever follow up mainline games Gen 9 gets will have it too, Gen 10 games will continue to have it, and so on. I'm sorry to say this, but I think permanent EXP All is going to be a permanent part of the mainline Pokemon games going forward, and it's never going to go away.
With that in mind, I think if you're not fond of the EXP All, the most you can hope for is that they handle levelling better in SV and future games. PLA for instance largely worked fine with permanent EXP All in mind because the levelling was changed, especially because the curve was well designed with respect to it and most importantly, they changed how EXP is gained and calculated in Trainer battles in that you don't gain EXP until you've defeated the entire Trainer's team, thus regulating the total experience you gain from Trainer battles. It was an improvement from Sword and Shield in that regard, even though the latter did handle the level curve itself largely okay with respect to EXP All despite the game not being all that hard in a vacuum. If SV handles levelling in terms of EXP gain and level curve better then people would likely have less of an issue with it.