The thing is there’s pumps that are good for mountain, or for road, some that are OK for either but not great at both… For mtb use something like a Joe Blow Mountain really does kick the arse of most pumps, not so much because of quality/expense, mostly juist because of appropriateness, it’s perfect for the job. My crappy Air Tower 2s are similar- high volume, inflates big tyres fast. The nicest pump in the world won’t do as good a job for a 30psi mtb tyre if it’s designed around inflating a 23c tyre to a million psi
When my other air tower dies I’ll replace it with a Joe Blow Mountain, but not til then