So I ended up getting a new phone - as pictured, a moto g34. I love it, it was $280 or something, and worth every cent. No buyers remorse. Migration from my old phone was probably 70% as easy as Mum's iPhone upgrade - much easier than I had anticipated - I haven't upgraded my phone for so long, it used to be painful.
I also did the fing that I was warned against - buying a mini PC from China. For $300 I got a Ryzen 4800H with no RAM or SSD.... on paper the Passmark score puts this at ~18500 vs the M1's ~14000 (although the M1 has faster single core score, but this Ryzen has 8 core/16 threads). My RAM hasn't arrived so I haven't powered it up yet, but my first impression is that it's very small - even smaller than I expected. The phone I got is an inch longer than its sides.
In summary, I upgraded my tech life for about 600NZD (without RAM). I may still regret this Chinese PC, but I'm willing to risk disappointment for a bargain. I will let you guys know how it goes in case you're curious. If you see it on Trade Me shortly, don't buy it!