Some ransomware affects your typical file formats that are able to be read on any system, so it really doesn't matter what you run. For instance, I think back in 2015-2016 there was malware being injected via the browser when infected PDFs were being read in browser. This affected all OSs. Things like that. Macs can actually get nasty stuff via macros being run on Office for Mac (go figure).
I run 100% Linux (yes I know that's going to get some eye rolling as people are tired of hearing/reading about it). It has it's issues, but nowhere near like on Windows. Sad thing is that it only has approx 2% of the desktop market. I am running in production a beta of what will come out this April as the next LTS release of Kubuntu. In production, main office rig. I haven't had one lick of problems compared to what happens with Windows on a regular basis on their supposed stable release (which is nonexistent as the current always updated model means that it is in a perpetual state of beta as it's effectively rolling release and since it's in a constant state of beta, issues are expected). Then, of course, on the Mac side, while it has been doing better, the first "stable" release of both High Sierra and Catalina had their issues, right off the bat. No system is perfect
As far as Windows and it's susceptibility. Some of it is users. Due to MS, in my opinion and only my opinion, being lax with security (how permissions are handled in Windows is no bueno at all, it's improved from the 9x era, but it doesn't compare to the Unix-like OSs (Linux/Mac) for extreme usability has really affected how people use the computer. Now your powerusers are a different story, but they don't make up the majority of the user base. It's those that just want to get work done and they view using a computer as a means to end (which is a shame in severally different ways, including efficiency in the workplace (like leaving money on the table in some instances)).
There are a few concerns in my mind with regard to Windows being a insecure:
1. Legacy code - the fact that we are hearing reports of zero days that have code that has existed in Windows since the 9X days is a concern. This also may mean that programmers are targeting those older APIs, which makes their programs susceptible as well.
2. Updates - ever since MS let go of their internal QA team a few yrs ago (2 or 3 yrs I think), updates really hasn't been all that it's cracked up to be. Now some haven't had a lick of problems and that's great, then you have some, like my dad, whose every major update ( 2 times a year), something has always fubar'ed his system and he doesn't have a slouch of a system (just put in a threadripper with 64GB Dominator, and an Asus TRX40), nor an old one.
3. Permission - In this case, how Windows handles them. Under the UNIX philosophy, no user is trusted right out of the gate. In Windows, if you only have a one account system, congratulations you are perpetually running in root/su/admin.
4. Telemetry - regardless if you have nothing to hide (which is a very poor excuse for the issue at hand), this is lines of communication that are open and the user cannot close. That means that is an area that can be possibly exploited. Unless you trust that they aren't a point of vulnerability, then that goes into how much do your trust your system?
Now, the listed items above are only my opinion, so take them for what that is worth.
As far software, running VMs is a great way to obfuscate the issue of software not running on whatever host OS that you want. Since you use Mac, I would highly suggest something that doesn't work off openGL, but off of Metal, this would take off the table VirtualBox, at least as of right now. VMWare is a very good solution (it also works off Linux). Properly spec'ed out, most of the software that we would run would run just fine in a VM. Shoot, I can even edit HD videos in realtime in a VM.