Thanks!
I felt like addressing it would be an unwelcome tangent, since the point was INT adding languages/ranks in 1e/3e, and not doing so in 5e.
But, here' goes...
While 4e didn't have Add. Lang or bonus ranks for INT, it did make INT more useful by using it to calculate AC & REF when higher than DEX, and did allow an INT-based character to make effective INT-based attacks, even with a weapon, using feats like Intelligent Blademaster or, a bit later, Melee Training. Plenty of other feats and utilities allowed INT or INT-based skills to be swapped into other rolls. INT was not only a primary stat for the usual suspects like Wizard, but a secondary stat for others, like the Warlock & Warlord in the PH1, for instance. On balance, it didn't seem like mistreatment.
Indeed, to bring it back around to your issue with 5e under-serving INT, you could also lift some of those functions from 4e, if you wanted.
Yeah, I know where you're coming from. I ran maybe three or four 4e campaigns and a few more one shots as well. There were some neat aspects to it, and some stuff that ultimately I realized I really didn't like. You've actually kind of hit upon both, simultaneously.
I'm not sure how far down this road we should go, but, briefly: My problem with the way 4e handles Int is the same as my problem with how 4e handles all stats. In trying to keep a good balance between the stats, which they achieve, what ultimately ends up happening is each stat loses a lot of uniqueness and verisimilitude. So, yeah, some people have good Int, and some have good Con, and some have good Dex, and if you have a big enough party you likely have people with every conceivable stat array...
But they largely use whatever stats they have in identical fashions, and the game makes it really easy to avoid using your dump stats for virtually anything that matters. The guy with good Con, at 20th level, doesn't necessarily have more HP than the guy with 10 Con. Their fort saves could easily be identical. One guy uses Con to attack, the other guy uses a different stat to attack, and ultimately... what's the point? It just ended up feeling very samey to me and my group.
There's very little about having a high Int or a high Cha or whatever that ever stood out to me as really defining. The high Int guy used Int for all of his attacks, even his attacks with a greataxe. The high Cha guy did the same. Etc.
I dunno. Ultimately this is a description of why the system
didn't work for me so it will no doubt come off as overly hostile towards 4e. I don't want to start one of those threads, so I apologize for that in advance. For all the stuff that ultimately didn't work for me, there were plenty of good ideas, some of which I have stolen for subsequent games. No edition warrior here.