Cheap and nasty silicone wax:
Washes off, but stops mud sticking as a result, covers scratches/swirls.
Expensive Carnauba wax (which is really just palm wax, like palm oil but with a name that doesn’t make you think of homeless monkeys in the rainforest):
Doesn’t wash off, but needs polishing in with a cloth.
Just wiping down with an oily rag (or a bit of clean cloth and chain lube if you’re posh):
Practically free, repels mud, nearly zilch effort. Gets marketed by Scotoiler as ‘ultimate bike spray’ (which is a good thing, because it’s crap as a chain lube).
Guess which one I use……………