Here (southeast US), lawn services use pickups, often also with a trailer. Most other services (plumbing, electrical, HVAC) use vans. Less sure about contractors, I interact with them less.
Most commercial services near me use trucks with or without a trailer. Painters tend to use vans, and some electricians. Everyone else has a truck with a logo on it. You can't tow well with a van, so it has to be a company that never tows.
Granted probably most people on here are CA or SV adjacent, which has a fairly idiosyncratic relationship with its service industries and stricter emissions regs.
I mean… do any of the commercial services in US use pickup trucks? It seems to all be vans? Why not to get a van then as a contractor?