well, I have few balanced issues;
1st off, 2handers are too weak, back in 3.5 when they did 1+1/2 str bonus, 2d6 could be enough. now they need 2d8 instead of 2d6/d12
longswords and rapiers have same d8? why? one weapon uses STR, other can use STR or DEX. Why isn't longsword d10?
Shortbow is simple weapon and longbow is martial? It's the same weapon, with different pull strength.
Same for light and heavy crossbow
Trident is somehow worse than javelin, yet it is martial weapon and javelin is simple. Shouldn't trident be d8 damage?
Dagger is too strong for simple weapon with those traits, either drop the thrown property or drop damage to d3
why does greatclub exist when quarterstaff does that job and can be used onehanded?
I can see a few problems with trying to improve two handed weapons.
150% Strength damage is only going to result in a crummy +1 or +2. Not really a meaningful advantage. Plus it requires math (the horror!) so I understand why WotC decided not to bother. And to be fair, they dropped that in 4e as well (but I'll get back to 4e in a moment).
So let's increase the dice. Well, you could say a heavy polearm does 2d8 and a heavy two hander does 3d6. But those crit fishing Barbarians and Half Orcs would be pretty sad when they only get crummy d8 or d6's! D&D isn't likely to switch to unorthodox dice any time soon. I guess you could have a d20 damage weapon, but I think some people would balk at the idea, lol.
And given that WotC wants people to either do more dice of damage
or get more attacks, the damage of one of these adjusted two handers would get out of control quick once you add Extra Attack or Haste to the mix, making any other weapon seem woefully inferior.
Now 4e cut down on static damage bonuses and kept weapons pretty much the way they are now, but there was a minor and a major thing that edition did to make this viable.
The minor thing was the Brutal property, which let you reroll damage numbers of a certain value. So you could have a 2d6 weapon with Brutal 1, meaning it's actual damage range is 4-12 instead of 2-12. Or a d10 weapon with Brutal 2, meaning it's damage range is 3-10 instead of 1-10.
The major thing was that characters got abilities that multiplied your weapon dice. And even your basic "at will" weapon attacks would upgrade (kind of like how cantrips upgrade) after awhile.
So you might have a limited use attack that does 4d6 instead of 2d6, and a once in awhile 6d6 attack. And at higher levels, even your regular old "I swing" is doing 4d6, and you'd have limited use 6d6 attacks and maybe even a once a day 8 or 10d6 massive attack.
But it's worth pointing out 4e was designed in a way that you didn't get a ton of attacks each turn. The Fighter's potential 4 attacks (plus Action Surge) is the main reason why weapons are so conservative in 5e, and other classes need to seek out additional damage elsewhere.
