I strongly disagree here: they are mopeds/small motorbikes that are mostly using cycling infrastructures.
This is not legal, nor right or safe for us cyclists.
Not safe, because they ride inpredictably at high speeds.
On the other thread we would like to see more kids cycling to school on safe infrastructures, yeah, along with your breakfast just eat bloke zooming at 30mph.
Of course, nobody complains, it's only cyclists that are inconvenienced, the population must get their delivery.
I suspect there's an amount of variation depending on where you are....
Around here the delivery riders are mostly on illegally converted / equally illegal Ali Express specials , pay sod all attention to the law and ride with excess speed (within limits; maybe 25-30mph at worst). Their attitude however seems to be very much one of necessity and despite constantly drawing attention to themselves through their abysmal riding they seem to keep their heads down and get on with it. Of those I've verbally abused I've never had one escalate the confrontation.
The kids on the other hand aren't out to scrape together enough to pay for another month in a 20 bed HMO. They're out for the sake of it; on proper electric motorbikes. They're travelling at significantly higher speeds (I reckon the last lot I saw were doing 40-50mph in a 30 zone); fuelled by each others bravado and stupidity. Their riding is intentionally reckless and provocative; raising the liklihood of an accident or violence if there's an alteration.
Of course I'd love to see them all off the road...