When I sat the ATPL many moons ago it WAS considered to be the equivalent of a Degree.
Not in my lifetime it WASn't!
There has long been a circulating myth about this idea, but in reality that is all it every was. I recall that many years ago (possibly
Hamble as I cannot find a modern day reference,) there was a specific integrated course whereby the
Open University provided a couple of "credits" towards a degree course if you successfully completed the programme. I seem to recall that had as much to do with the peripheral study as it did with the ATPL content. It certainly didn't provide an academic degree of any sort.
Even today, similar
quasi courses pop up from time to time whereby the ATPL training may provide an embedded element of a degree course, but I have never seen any correlation or suggestion of "equivalence" between the two, nor would I really expect to.