Sure, you could build a barbarian with dex as a dump stat, if you wanted to emulate that famous hero Conan the Klutz, and be lousy at melee as well as ranged, due to poor AC and initiative. Hell, you can make your strength 8 too. The point is, player decisions are supposed to have consequences. You seem to want to eliminate any meaning to player decisions to the point where you might as well roll a d20 and if the score is greater than 1 the monster dies!
It seems to me that you are unaware of the martial ability: Extra Attack. This works with bows!!!! Thus ALL martial classes (even monks) have at least twice as many ranged attacks as non-martial characters*! *(warlocks excepted)
As for fighters, sure, a heavy armour fighter might dump stat dex, but they could just as easily be an outstanding archer. Player choice has consequences. The system does not force a fighter to be poor at range, the player has to choose it. And even a dex 8 fighter can gain abilities to help in ranged combat: an Eldritch Knight can learn a ranged damage cantrip, keying of intelligence; many Battle Master manoeuvres work with ranged weapons; the Champion's improved critical applies to both melee and ranged attacks and they get an extra fighting style at level 10.
As for paladins, they have so many spells and support abilities that there is always something they can usefully be doing. I'm surprised you even bring them up.
I somehow liked and favorited this post by accident (using the mobile app). It's a fine post, but not THAT good.

My son had a dwarf paladin with an 8 dex. It was done because it was a fun concept to have a slightly clumsy, well-meaning dwarf in heavy armor as much as because it seemed pretty efficient when wearing said armor.
We only played that game up to 4th level, and up to that point thrown weapons worked fine. I expect at higher levels it would have started to be a problem. A bow really wouldn't be a good solution for that character. We would have had to really rely on some system mastery for careful spell selection and maybe the generosity of the DM (or luck) in getting some magic items to cover the deficiencie. Or, of course, the kindness of other players using their spells or abilities to help out.
So it is not an insurmountable problem, but one that would definitely require some thought and pre-planning.