By not going through a car wash your doing the paintwork a favour anyway😆. In addition to marring the paint a bit each time, these automatic car washes never wash wheels inside the barrels, door shuts, rubber seals etc etc, and seldom if at all dry the car leaving water spots even if they add rinse additives to the water.
I appreciate not everyone has the driveway or physical ability to wash their own car and in those circumstances your choices are limited. Personally I would leave it dirty for longer and just take it to a local detailing company to wash it properly which is typical £15-20 depending on what’s done.