This is a deeply personal decision and I categorically reject any kind of moralization around frugality.

Fair enough on the personal decision part. I'm less interested in telling people what to do and more interested in whether the premise ('nicer things = happier') actually tracks with how human satisfaction works. The research suggests it often doesn't, which seems worth knowing regardless of what you choose to do with that information. [1]

1. https://pubmed.ncbi.nlm.nih.gov/690806/

It's a bit more than just a personal decision. Overconsumption is ruining our environment, which we collectively have to share.