What Doug get from getting thumbs up
Nothing, just praise from another rider
You also get an accelerated Drops accumulation rate for a short time.
Plus, as also mentioned in the thread below, certain threshold numbers of ride-ons in a single ride gets you extra-credit badges (“You’re Famous”, “Bigger than Jensie”).
Doug get happy
At lower levels I wanted to get more drops so I could buy reasonable equipment. So I cultivated a lot of followers by following people who I thought would follow back, and giving lots of ride-ons in game since some people reciprocate. Most of the ride-ons I get are from people who follow me who are not actually riding at that moment - they just push the button in the Companion app and all of their followers who are riding get one. So if you have 1000 followers that’s plenty to get a constant stream of ride-ons. Once you get mid-way up the levels there isn’t much point in collecting drops since you’ll already have good equipment by that point, so now I don’t spend time trying to get more followers (but I still follow people back because why not).