The SMB theory seemed appealing to me initially, but alas in my case I don't think it has anything to do the Kps I suffered for months.
Someone pointed out that the the SMB theory had to do with mounting SMB shares not hosting them anyhow, and that was never my problem (that I noticed). Further, if it were mounting SMB shares I'd think the problem would be far more widespread as Google Drive's client is now SMB based and I imagine millions of Mac users use that.
In my case, after trying numerous fixes and wasting hours and hours researching, including even some support from the developer of EtreCheck, I decided to rebuild with Monterey's erase all content and settings option in System Preferences. It's been smooth sailing since. To be clear I went with that option simply because it's the quickest way to begin the rebuild process.
After the clean rebuild I checked with kextstat and noticed that com.apple.filesystems.smbfs is not loaded by default. In fact, it wasn't loading at all until I installed Google Drive. What I've noticed is that com.apple.filesystems.smbfs just happens to be the last kext that macOS loads, perhaps because it doesn't load by default but when it does get called it then goes on at the end. If since boot you mount a flash drive that is exFat based or connect a USB dongle of some sort then corresponding drivers may load and appear more recent, but I presume if I reboot then com.apple.filesystems.smbfs may again be the last one to load (I haven't tested that) for whatever reason and so perhaps that is why it appeared in as the last loaded Kext in my KPs.
Crossing my fingers here it's been 5 days and still no KP. I deliberately kept third party software to a minimum this time. I'd like to install Amazon photos (for upload/backup) on the Mac but am waiting until I am sure the problem is fixed with the limited set of software that is on there now.