While I’m not disputing your point I have used such an adapter for over a year with no problem
Well, i have stumbled upon this question like countless times on the forums, i think from all the replies i read, it is more of a general consensus to avoid doing so.
Iam not super technical but if i can remember the reasons correctly, first to get benefits of balanced the whole cycle should be balanced inputs/outputs/cable.
In addition, single ended 3 pole share ground for left and right, while balanced 4 pole (say 2.5) have a separate ground (L- R-) for each signal , so there might be a risk of shorting the 2 (L- R-) together and cause damage.
this was mentioned by experienced guys here on the forum and even some vendors.
So if there is no benefit sound wise + added risk, not worth it.
As for why its been working alright for you , thats beyond my knowledge i guess
You can try to search the forums for more info though.