Yes, definitely.
I've called UX designers out a couple times on the aesthetical complexity of their designs: if you award GOV.UK's quality a prize [0], why don't you mimic them instead of Google?
[0] https://www.gov.uk/government/news/govuk-wins-design-of-the-...
Part of that involves really simple layouts, very high contrast text, legible fonts, compatibility across many devices, simple language etc.
It's certainly an added benefit that it gives an appearance of austerity, but that's more a byproduct of simplicity.
Governments generally don't have that requirement. So GDS doesn't need fancy branding and other concerns can take priority. It's remarkably refreshing.
It would have been so easy to just cargo-cult whatever is fashionable in the private sector. It's kinda miraculous they didn't. A mark of thoughtful, self-confident professionals. Bravo!