I am not entirely sure what role the all-too-prominent LEVEL plays in the game. So maybe this doesn't work... but lately, I'm thinking it might make more sense to have a plurality of levels, one for gardening, one for animal husbandry, etc.
levels used to matter, but then they were very purposefully made to not matter. they were purposely divorced from from gameplay and skill [other than granting an increase in energy tank size each level].
XP is just a way of proving how awesome a player you are. which is important if you want to be competitive against all the other players in the game or amongst your friends.
XP is like points in the game "Pac Man" or "Donkey Kong". A number at the top of the screen that doesn't benefit your character at all but gives you a "high score" that can be posted up on a leaderboard.
the leaderboard could maybe be improved to show the breakdown of where each player's XP is generated, and then grouped into "most XP gained gardening" or "most XP gained cooking" leaderboards .. but i don't think XP is going to have any mechanical benefit to the game [other than increased energy tank size]
I guess a lot of people enjoy having an overall level that shows their cumulative progress in the game. I do think it makes sense to have xp or levels tied to specific skills as well, so if you need a certain job done, you know you need to find a level 10 or higher gardener for example.