I would second the don’t replace unless it’s **** thing as other posters have said. If I upgrade I take into account the resale value of the parts I want to replace.
Forks might be your best bet. New crankset prob won’t feel that much different, unless they have play. If you changed your shifters/ rear cassette/ front and rear derailleur you would feel a big difference in shifting.
But yeah forks would be worth looking into. Not cheap though and sticking light forks on a heavy bike (is it heavy, relatively speaking?) may not make much difference in weight wise but would defo give you a smoother ride up front.
I would check out the classifieds on here, for the price of some nice new forks you might be able to get a decent set of forks plus other bits you are looking at changing. Edit…sorry has already been mentioned but worth looking at.
The other option is looking for a nice second hand bike and sell this one?