My googling shows that fireworks are ILLEGAL in some places in Mexico. Sparklers are allowed but not the blow up stuff.
There seems to be towns with fireworks factories which may make access easier and legal.
Also I am not sure that EVERY DAY is correct either. These stands may come out for holidays like Christmas, New Years and Mexican Independence type celebrations.
Adding a Gabbin comment on one of his Mexican DUI checkpoint posts:
Gavin Seim for Liberty There’s no crime without a victim. That’s how law works.