That stat issue is something I also encountered in PF:WotR, where the main stat to pump for one character is intelligence (or wisdom, depending on background, 3.5e is extremely complicated when it comes to building), though.
RP-wise it's even right that a CHA based character is the face of the party, but I also feel a bit like "mostly it's CHA based classes for your main" here.
But I don't think addressing Larian is right, the problem lies much deeper in the D&D rules, which don't currently allow replacing CHA at least with INT or WIS (something that 3.5e allowed to SOME degree between INT and WIS).
Yes, it is in part the ruleset, but if you can role for stats, with patience, you can still get a respectable charisma score on your main regardless of class. If you ever rolled for characters in Solasta, you will be aware that your total stat budget can be dramatically higher than the standard array. Also, when it comes to skill checks, charisma based roles in combat are FAR more common than any other skill check.
Also PF:WotR had the advantage that any party member can take a skill check in most cases, regardless of who is initiating the dialogue. Its certainly way more complicated rules wise (personally, I liked the depth), but I never felt hamstrung by the need to play a high charisma character or have my RP options significantly restricted.
