I use an SKS Kompressor floor pump with a Hirame Yoko head. I bought it because it's simple and old school, and it was no longer possible to buy Silca or MDI pumps new when i got it IIRC. The stock SKS head is OK, but the Hirame is much better. It's super reliable and a joy to use.
In a bike shop, where the pumps get used all day long every day, pumps would have to be pulled apart to grease the plunger every so often. The rubber in the heads would need to get replaced periodically, especially with Silca track pumps. Really though, very little maintenance required for the old school all steel pumps. Might have to look at them every year or two? Multiply that by 10 for home use.