Ignoring the arguments one could make about this making it "more secure" it's clearly disrespectful to the power user that doesn't want to beg Apple's permission to use their computer. I'll grant them their security claims are sound,

I wouldn't say they are sound. First, macOS provides the freedom to install your own applications (ok, they need to be signed and notarized if the quarantine attribute is set) and it's not the case that the Mac has mass malware infestations. Second, the App Store is full of scams, so App Store - safe, external - unsafe is a false dichotomy.

Apple uses these arguments, but of course the real reason is that they want to continue to keep 30% of every transaction made on an iPhone or iPad. This is why they have responded to the DMA with a lot of malicious compliance that makes it nearly impossible to run an alt-store financially.

(Despite my qualms about not being able to install apps outside the app store, I do think they are doing a lot of good work of making the platform more secure.)