I have a very similar situation: I loved using MacBook Pros as my work computer for over 10 years now, but while my job consists of 80% of cross-platform Java development stuff, it also includes working on and compiling various custom binaries (from big fat Chromium builds down to little system-level libraries and Linux kernel modules). All three major OSes are targets: MacOS, but most importantly Windows and Linux - especially Linux, because that's the main production environment on which our end products usually run, while the others are mostly needed to enable our devs to develop on their preferred platforms.
Windows and Linux MUST be x86_64, because that stuff needs to run on that arch eventually - it's of no use if it "works on my (ARM) machine". The Mac platform has, until now, been the ideal platform for my work, because it comes with by far the best OS on which I can be as productive as possible, while at the same time being able to execute all three targets within performant VM environments, greatly simplifying all the low-level development tasks as well as testing and experimentation. Even USB hardware could transparently be routed into the VMs - something that's also very important for me, as I often need to deal with weird and rather unusual periphery, and which is highly problematic when working on remotely hosted VMs, which I did try for a while back then when MacBooks had that RAM cap at 16GB in order to be able to utilize more memory.
I'm still good with my current MacBook Pro for about two years or so, which gets me well into the transition period. I know that I'll definitely be tempted to privately buy a replacement for an old 2011 MacBook Air, which I still use for light browsing tasks and stuff at home and which will be totally fine if it's ARM-based. If anyone happens to come around with some kind of VM emulation solution for actually virtualizing x86_64 OSes on the ARM-based Macs - there at least seems to be a demand, so I haven't lost hope that one of the likes of Parallels or VMware might take up that task - I'm going to give that a try and see whether it's a solution to my remaining 20%.
If that doesn't work out, I'll have to consider either switching to ARM Mac regardless and keeping the old machine (or another PC laptop or something) around as a second machine for the low-level Windows/Linux work, or ditching the Mac platform and moving to a Linux-based machine as my main computer, with Windows in a VM, and maybe getting a small ARM Mac as a "sidekick" for that bit of MacOS compilation and testing work. Either of those will be worse than my current, nearly-perfect setup, which was originally enabled only by the beauty of ISA compatibility between the Mac and PC platforms.