It would be hard to get much done with a 7k cap including the trailer. We致e had plenty of debate before about tractors doing a trucks job. Are they easier to make legal for more weight?
Although this is way more common in Scandinavia, the other countries in Europe will also do it but not as much.
It's easier and cheaper to get the drivers license for the bigger tractors and it's less expensive having tractors doing trucks jobs. With a tractor, you wouldn't need the yearly vehicle inspections, tachograph and tachograph inspections, and all the associated stuff. Also, I don't think you have to renew the drivers license for tractors, or at least that often compared to trucks.
This works better because of the smaller travel distances to the jobs since the countries are, for the most part, small. At least compared to the US.
My country actually don't do it that much. For those that can justify the expense of running a truck, they mostly run 20 ton dump trucks fitted with Pallfinger cranes. It's a good general purpose truck.
And this smaller 5.5 ton one:
This one can get registered at light duty and can be driven by anyone with a B category drivers license (can drive all vehicles up to 7700 lbs gross weight), but gets capped at 7700 lbs. Or can be registered as commercial and get a 5.5 ton gross weight capacity but needs C category drivers license (can drive trucks without trailers).