Is there ever a legitimate reason to use " whilst" instead of " while"?

This particular British person uses 'whilst' seldom, but when I do use it, it's to show a contrast:

Emmy enjoyed classical ballet, whilst Josephine preferred tap dancing.

I never ever use it in relation to time. Susan was busy knitting while John watched TV.

Brits say "whilst". We only say "while" in the US. I don't know about the other English-speaking countries.

Yes, it's common usage here in the UK.

I use 'whilst', but you can use any form, as you like.

I use it when I want to sound "fancy."

yes too diffeent words

The legitimate reason is living in a country where it's standard. My British and Australian friends, for example, use it.