They are widely used in Spain too, and on the 3 occasions I have had to call an electrician it has been these connections which were at fault.
I guess we are getting much more sophisticated nowadays, but wire nuts have made millions of connections, and while i don't like them, or the principle on which they work, they are still popular in some areas. One thing I do like about the Spanish wiring systems in houses is that they do seem to stick to zones, and every room will have at least 1 junction box where all the cables connect and can be exposed by removing a slim, flat cover-plate., where the singles, in conduit, are easily accessible...albeit terminated in wire nuts. One chap who came to fix a dodgy lighting circuit had to cut off a wire nut and I gave him a few Wagos to try...he liked them, and I take him a handful each trip as a bit of a standing joke. 2 5-ways = 1 beer! God, let me out of lockdown, please!