As a casual enstars fan I would never RP from it because there is way too much to read for any given character.

I think it depends on whether the game bases its gacha on new characters (like Genshin) or new cards of existing characters (enstars, twisted wonderland). Games like Genshin are always expanding their cast, so you naturally get less content for older characters once their newness has worn off, though they may come back for events here and there. Enstars/TW on the other hand are building up the lore of their existing characters with every new event or card story because they rarely if ever add new characters.