Every single one of these guys across almost all genres uses this bizzare electronic jazz nonsense to do transitions and montages. You see it in car vlogs, travel vlogs, tech vlogs, etc. Are they open source randomized jazz bots? Cheap tunes made by sweat shops in Bangladesh?
You can even see it coming: "Intro muzak montage in 3....2....1....."
Random examples from my youtube feed....starts at 32 seconds