Make gear context sensitive. That means the best gear for raids only comes from raids. The best world content gear comes from world content. The best M+ gear comes from dungeons.
This way people aren’t “forced” into content.
A simple solution would be adjust the ilvl lower if the wrong gear is worn.
No, don’t want to carry four sets of gear like its bfa
yea having to carry pvp gear and content gear in wrath was bad
No, thank you. This idea is bad. It’s bad^10 for people that play multiple roles and content.
No one is forced.
Imagine playing this game and thinking we need a “gearing solution”
literally talking about WoW the easiest MMORPG this world has ever seen with tons of QoL and ways to quickly gear up.
Wild. 
I mean, I would be all for it if we could create a sensible system to go with it. So for example, if you have collected the PVP gear, it gets stored in something like thetransmog system. then you go out and collect your PVE gear and it gets stored in the same system. once you have it stored, you can go into that system to upgrade it or swap it out as needed, and never have to carry the gear with you. Then before you run some content, you simply drop down the gear manager pick the set that you need to use and it auto equipped see your character because it was saved to your characters account in that system. but that’s a very long convoluted scenic route just to tell somebody to stay in their own lane and get their own gear 
No one is “forced” to do any content as it is now.
what’s the solution to now people don’t venture outside their lane? less people to raid and m+ with? more bag space for everything?
Bad idea to carry 4 sets of gear just to do content. We need a Swiss army knife set one set that does it all. Lets try and focus on preserving bag space.
And then later the solution to the gearing solution problem will be infinite bag space!