No. Most of those people are self-employed, so you are usually already paying 100% of the compensation directly to them in the first place. Tipping is for when someone is doing work directly for you, but as an employee of another party.
Does one leave a flight attendant tip in the seat or in that envelope in the seat pocket? (Handing a tip to someone directly feels so gauche, like I'm pretending to be some fancy person.)
In my city, it is common courtesy and sometimes expected that you say 'thank you' to the bus driver when getting off at your stop. It's not too much of a stretch to the scenario where bus drivers are tipped, except that most bus riders (at least in the US) tend to be poor. Maybe we'll have bus drivers tipping well behaved passengers instead lol.
