Day care and nursery were blows to our progress as well. A big part of it was that he had to wear clothes.

He was fine neked but as soon as clothes went on he'd forget (probably felt too much like a diaper). Switching to boxers for him helped a wee bit.
But yeah, nursery and day care demanded diapers until 24 months, and so did the local pool we used and the play area we went to. It was really silly and annoying, but I can see their point of view. If you had to take a potty learning toddler to the toilet and help with clothes and wiping etc as often as mine needed to...and you had 10-15 OTHER kids doing it too...well you'd practically need one-on-one care and that's not practical for daycare.
I will say that every now and then we used underpants with panty liners (super absorbent super thin pads) and they were none the wiser and he felt big for getting to wear underpants, but also protected and safe having an absorbent barrier for just in cases, or just those initial spurts that warn boys "I have to pee!"