IRL i only used a powerwasher at the station for car cleaning and tbh that's kinda boring (because most of the time when i did it, i was in a hurry)....
When Powerwash Simulator was free on PSPlus i wasn't realy looking for it, but a friend of mine said we should give it a try since it has MP....
Long story short: He quit after 5-6 levels and i was addicted^^ Platinumed PS4 and PS5 Version + all DLC and got Powerwash Simulator 2 at release (which will also get DLC's soon).

To the people who are looking for a releaxing game, give it a try, it's calm, it's chilling and so satisfieing^^