Ever operated frequently into the real Class D towers, Tossbag, to see if this actually happens? Or are you speculating?
Matter of fact Captain I make several airwork bookings a week at Class D towers. The bookings are usually fit in around the RPT, or now, Part 121 ops. That ain't a problem, it gives the IFR students something to aspire to when they're listening to the bigger metal, it also helps them understand how the radio should be used. Most of the 121 ladies and gents are courteous and thoughtful, operating in these theatres helps the student understand why they're holding and the importance of fuel planning and that it isn't just a static number.
The VFR's get absolutely shafted in this country when it comes to Class D in particular (although the one I'm flying most into recently is doing a good job, probably because prior to the covid lockdowns coming off they pretty much only dealt with lighties).
'Have you got a plan in the system?' Ask any VFR how often they've got a clearance over the top of Melbourne, Sydney or Brisbane, in particular prior to covid.
There was a report done on an accident that killed two people in the not too distant past, I doubt it will see the light of day, it was scathing on the part two officers played in denying a clearance.
And I reckon we swap logbooks if you want? I'll bet I've flown into more Class D,
real ones, and whatever other ones you're suggesting exist. I can also supply my log in for the airwork bookings if you like?