That's assuming they knew such a thing was available. I've come across a few sparkys who have no idea what's available - and won't enquire. One example :
I was doing a network install for a client, and their contractor's sparks was doing the dado trunking - some rather nice Rehau stuff. I quite likes some of the details, like the way the lid for the bottom section was integral to the back, so formed a tray that cables would stay in by gravity rather than the usual faff trying to get the cables to stay put while you get the bottom cover on.
On one run I had to fit 24 network cables plus a 10 pair phone cable in, and he'd left me just the small section at the top - while using all the rest for 2xRFCs (4off 2.5mm T&E) and a 10mm bonding cable ? First thing he was 110% certain of was that only the mains can go in the middle/bottom section and network cables must go in the top section - otherwise they aren't isolated. Apparently, the plastic used in this trunking only insulated one way round ?
So I mentioned adding a divider to make it into 3 section trunking. "Doesn't exist" he stated with complete authority. Unfortunately, back then I still had a rather basic phone, and that together with a poor signal meant I couldn't look it up on site - to find that yes, they do in fact do a divider. Had I known I'd have just insisted on getting the divider, but not being able to say "yes it exists" there and then, there wasn't enough time without holding the whole job up.
Luckily there was an alternative route I could take the phone cable, it was just more work.
TBH, his workmanship was top notch, he was just an idiot who didn't understand how sectioned trunking works or what's available.
And for good measure, he said "it must be nice when someone else does all the hard work for you". In a rare case of self control (bear in mind I'm autistic and tend to say exactly what I'm thinking), I managed not to give him some rather painful instructions as to what he could do to himself.