Things I spend too long thinking about

When did everyone start saying 'whilst' instead of 'while' in text form?

I mean, I know it's grammatically valid and correct and all that but it's something I've suddenly started noticing more and more, pretty much everywhere.

It just scans as, kind of jarringly weird and inappropriately formal for some reason. No one actually says it verbally. Just in written form.

I'm sure it was never always thus and is a fairly new thing.

While is a more contemporary and 'friendly' word than whilst, which fairly or not has connotations of thee, thou, amidst, amongst etc - ie: old fashioned, a bit frumpy and stuffy. For context, I'm a commercial writer and it's one of my jobs to make dull stuff understandable, approachable etc. And I'll still always use 'while'.

However, as you say, whilst seems to have been gaining in popularity. I reckon it's to do with some people wanting to appear a bit posher and better educated than they are, and see the use of arcane language as a weird step in that direction. The best example I can think of right now is the prevalence of myself and yourself instead of me and you, which drives me crazy.

As sub-editors, we were told to change any instances of 'whilst' to 'while' in our newspaper style guide and I've been doing the same ever since. I left the industry nearly 11 years ago.

That's all I've got, I'm afraid.

Good. Glad it's not just me.

I think it also got a popularity bump as something of a meme-ish piss-take of people using it to sound intellectual. I’ve seen it used a lot that way, anyway.
See also: ‘M’lady’ to make fun of incels.