I doubt there will be a native GUI renaissance, look at the mac app store, it's not making a dent in the global direction and it's available since years. Ok it's only for a single platform, it's even worse on the windows app store!
I think there is no way back for desktop apps. Browser is the best sandbox available.
VM hypervisors are even better sandboxes. I don't imagine any browser will be more secure than for example a VirtualBox or VMWare VM, unless the browser itself literally is a VM hypervisor.
Obviously it would need to be made much more transparent to the end user, and integrated as a background technology. I am not suggesting that non-technical people should be trained to operate VMs, that's ridiculous.
Those 2 places aren't not the only places one gets software for either of those platforms, and are not really solid indicators of the popularity of desktop apps.
The Windows store especially isn't, because (as far as I understand) until somewhat recently, you were locked to only publishing UWP apps to it.
