Or just different loot. Destiny actually had a fairly decent approach to this. Some gear was PvE only from enemy drops, and other gear could only be found in the PvP shop (which required grinding currency in PvP to purchase). There was some gear that was categorically better for builds, but the devs tried to keep the exclusive stuff fairly balanced. So like the PvP stuff wouldn’t try to make you outright overpowered in PvE, for example. It meant you could take the same gear across the two different modes, without being able to simply get OP by focusing on one mode entirely.
The devs struggled with balancing the gear between the two modes, (looking at you, Gjallarhorn), but the idea wasn’t awful.