Personally I think it comes down to cost and availability. They cost around 5000 Euro if not more, and they take sometimes months to be delivered.
This depends heavily on the bicycle. If you get a bicycle with hub gears and coaster brakes you'll likely be riding it until the chain literally breaks in half. If on the other hand you get a bicycle with a derailleur you'll be fiddling with it every quarter if you want to keep it operating nicely.
I got a new bicycle two years ago. It hasn't had any maintenance other than inflating the tires and replacing the bell because nincompoops keep pulling the hammer off when it's parked. Still rides like new.
Personally I've added a motion activated alarm on top of that, but that's mostly because I got tired of people fiddling with my bike and breaking shit.
Doing the above should get most thieves to try and steal the next bike over instead of yours. Still might be worth getting theft insurance though, depending on how bad it is where you live.
Don’t get me wrong, I’d love to buy and use one. But it’s still too expensive to be a rational investment, especially if you are on a budget.
Apples and oranges. You can get cargo bikes second hand too.
You don't really need a cargo bike, but it's a nice to have.
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