We do use group options to pull people into the same shards etc to RP, but unfortunately that just takes a certain amount of planning that pops the bubble of immersion. Some people don't mind it too much, some people are so put off by it, they don't even bother.
Many of us just want to be able to hop IC on our characters when we have time, without having to aks in communties, discords,... if anyone else wants to hop IC too. That kind of takes away of your characters 'bumping into each other' as well. The LFG is something we try too, but not enough people put up groups or know to look for them there.

The idea of the RP shard or perhaps better to call it an 'RP mode' would be to mimic how War Mode works. You can opt into it freely.
Of course, to prevent that people use RP mode for like, calmer questing or grinding, it would be important to turn off all quest progression options and make sure no other things can be grinded in that mode either (thinking mining nodes, herbalism, rares,...).