No, I'm not really interested in PlantSims becoming a life state.
I've played several PantSims, but it's been a while since I played my last one. If I remember correctly, I didn't have a problem keeping them hydrated but I did run into trouble keeping their hunger bar up, especially at night. I think they had to siphon energy from plants and trees growing around their homes. The plants took a hit from being drained so they weren't allowed to use anything in their garden unless they had planted a few spares to use for energy. I think we had grow lamps in Sims 2 but we don't have anything like that in Sims 4. I recently read that an ice cream maker can be used to make plant matter by a Sim that has Level 8 Cooking. I'm going to have to check that out.
A couple of years ago I had Salim Benali become a PlantSim so he could work on the Bodybuilder aspiration. The energized buff lasted long enough for him to finish the aspiration without taking any of his lazy naps. He was never the same after that. He never dozed off during dinner dates or anyplace else.
I never wanted any of my PlantSims to stay a PlantSim for longer than the 5 or 7 day buff they got. At least as they exist now.