I recently sold my 2013 Mac Pro (trashcan) and got a tricked out 2020 27" iMac to buy some time before being "forced" into Apple Silicon. I may be wrong but I still see some growing pains before things settle down for photographers with the new Apple chips. My new 27" iMac is a 10 core i9, I got 64GB of RAM from OWC (saved about US$1,000), the standard graphics card (I do no video), and went all the way with the 4TB SSD. It still smarts that the storage is not user replaceable on any of the current Apple computers. It's likely way more than I need and was pretty expensive but this is a machine I use daily, for pleasure not remuneration, and I feel the cost is justified. I don't really have a ny specific advice, you've already been give some good ideas but thought I'd share how I responded to having an old computer in the age of Apple Silicon and COVID. Best to you and be well.