I live in South Holland and I still say to foreigners that "I am from Holland" meaning "I am from The Netherlands".

Pars pro toto... ;)

Technically correct but Holland has long been used as a strong branding name for the entire country. It wasn't until recent that they started to make a better distinction between the two.

Philips, ASML, Inventum and many other companies used "Made in Holland" on their products despite not being in the provinces of North and South Holland.