I am very disappointed in Parallels' dropping of support for "macOS 10.5 to 10.8" on Intel systems.
I have some important legacy 10.7 VMs that I refer to regularly (this is not professionally unreasonable), and if upgrading to the current version I will lose that usable trove of data and information.
Yes, I understand that Silicon processors are now Parallels' main focus, and that Intel processor systems in the Mac marketplace are dwindling. If using Silicon, all those older Intel VMs now must be reconstructed with ARM versions of whatever the guest OS is. If you have close to 100 VMs like me that's an inordinate amount of work, and the reconstructed VMs will never be the same as what was previously constructed.
I made a decision when purchasing a MacBook Pro at a time when both processors were available, and while I could have gone with a Silicon processor, I chose Intel so that I could continue with older work that was made with *your product* to run hyper threading natively.
So to see these older versions of macOS drop off is a real blow, and personally it dissuades me from updating to the newest version, even though there are bug fixes and improvements I could benefit from. I think it is a poor decision that affects your professional user base. We buy Parallels Desktop to run alternate versions of OSes, and limiting those versions makes your product weaker. (Hell, I even run a VM version of Next OpenStep, would that be cut? You're killing your enthusiasts here!)
VMware Fusion Pro 13 still supports macOS versions back to Mac OS X Server 10.5, and while the integration to macOS isn't nearly as complete as Parallels Desktop (kudos for that), they are not abandoning older versions of macOS.
If I understand this trend correctly, it is just a matter of time before all Intel support is dropped from Parallels' products in favor of ARM, and I think that is a poor decision.