The option to Enter Raids without full party

I wish I can enter a raid without full party, so even when I’m super overgeared, i can still have some challange.

So lets say I want to try and solo Valtan, currently the only option is to do a bus, and i hate doing buses. But with the ability to enter the raid alone or with 2~3man, I can still enjoy the raid without leeching from new players.