Yes, but....
?..it depends wholly on an individuals fitness.
15 years ago as a relative novice, i could achieve 18mph on the flat no problem, but it was with some considerable effort, usually pushing for all I was worth.
5 years ago, i could easily spin at 18 mph. If i pushed the same way i did 10 years earlier, id be doing 24mph..not 18. Those days are gone for me sadly...
Fitness dictates It all, not the cadence or a particular gear .
I occasionally got sore knees early on, mashing away for all i was worth, then tried spinning, which seems counter productive at first.
It may well be OPs cadence isnt responsible...equally, it may be, its just one of a few things to consider.