I agree that martials get fewer "unique" stuff, but weapons and armor proficiency are not that special.I appreciate the attempt to balance the weapons and armours logically. The official ones are a bit of a mess. With armours particularly there are just a lot of utterly pointless choices.
But I don't understand or approve the idea of getting rid of proficiencies. Having proficiencies allows us to have some weapons and armour that are better, the cost just is that you need a proficiency to use them. Also, the armour and weapon proficiencies are in the purview of the martial classes, so just giving their stuff to everyone for free seems really unfair. Martials really don't have too much unique stuff!
And how is martials niche will be affected if wizard has a greatsword proficiency?
Let's take 5th level wizard and 5th level barbarian.
And give wizard highly unlikely 14 STR.
Barbarian will have 18 STR as expected.
VS. AC15 target. Barbarian uses rage and reckless attack(as they do 99% of the time)
wizard: DPR; 4,5
barbarian: DPR; 21,84
I dont see barbarian losing too much sleep over wizard that is doing 1/5th the damage with the same weapon.
wizard will do DPR; 6,6 with firebolt.