But let's assume they are small scale personal beater pickup trucks. If they can't afford a nicer work truck and aren't able to purchase professional grade equipment, do you think they will be able to afford electric alternatives and extra batteries, etc?
Regardless, pro or consumer, they are all the same level of loud you are annoyed with. If you think it's bad as the person hearing your neighbors yard being mowed, think of what the operator is dealing with (ear protection is a must).
Maybe I'm indifferent because I used to do landscaping and spent time around all kinds of loud machines, but imo it's not that big of a deal. It is loud, I'll give you that. But pro mowers are fast, because more lawns is more money. So on a regular city or suburb lawn they are in and out in 5-10 minutes. Walk inside, or close the window, or run an errand. Sometimes people's occupation is an inconvenience to us, but it's a tiny fraction of your day and there are plenty of things you can do to minimize it.