I like the way it is now, where any character can use a shields but not all characters are proficient.
I voted "yes" on the poll, but in that respect I do not want to hand out shield proficiency to everyone, I just want them to be able to use shields like they can currently (with disadvantage on strength/dexterity attacks/saves/checks as well as no ability to cast spells if not proficient).
I think the same should be true for weapons. TBH I would like to see them remove all weapon proficiencies from Wizards and Sorcerers. They can still use any weapon they want, but don't get to add proficiency bonus.
This is how I would distribute weapon proficiencies:
Fighters: Proficiency in all weapons, including Simple, Martial, Siege Weapons, Improvised Weapons and any magical or high tech weapons like lasers or modern firearms etc. If it is a weapon of any sort fighters get to add their PB to the attack roll.
Paladin/Barbarian/Ranger/Rogue/Monk: Simple and Martial weapons
Cleric/Druid/Warlock/Artificer/Bard: Simple Weapons
Sorcerer/Wizard: No weapons
I would also take away all weapon and armor proficiencies on caster multiclasses.