PlayStation will support Fortnite’s shared wallet, beginning with update v20.40, which means following that update, V-bucks purchased on your PS5 or PS4 may be used across all platforms that also support the shared wallet.
This leaves the Nintendo Switch as the sole platform where V-bucks you purchase cannot be used for the same account on other platforms. In the case of any V-bucks earned through the battle pass, those are available across platforms.
Now, players can purchase microtransactions on their PlayStation device, and carry on using them when hopping on to play on PC, and vice-versa. It’s definitely a heavy contrast to Sony’s position just a few years ago.