Not often, if you’re running non-fiber reinforced filaments. even standard brass nozzles can get 1000 hours on them before you start to get loss of print quality. And hardened nozzles have practically infinite life in normal plastic.

Better off getting multiple sizes though. A default 0.4mm nozzle is a nice middle ground. 0.2mm gains a ton of detail for small parts. 0.6 and 0.8mm nozzles can drasticall ly reduce print times for large parts and creates better overhang/bridge surfaces.