Many ATC instructors have been training students to say "Remain outside controlled airspace" as the first response to an airspace crossing request, instead of a dynamic assessment of the traffic conditions at the time and an appropriate response. You could almost issue a clearance in the time it takes to say it.
It's a school of defensive parrot style brain dead ATC which is more about arse covering than safety. Safety can be equally achieved without having to say NO to every request.
Personally I am not a fan and I still like to offer the best and most flexible type of service available given the circumstances. Luckily as a licence holder we're still allowed a degree of personal choice within the framework of the rules.
I can only think of a couple of UK units (pre COVID) that have genuine traffic reasons to deny airspace crossings all the time. Everywhere else is just laziness or lack of skills/confidence.