It's not thaaat clunky. With my phone I click the download link, it downloads the apk, asks me if I want to allow to installing apps from the browser and then asks me to install the app. Installing a program in Windows is more complicated 95% of the time.
On top of that, if you have a rooted phone, you can use F-Droid to automatically install updates. For me updating apps from F-Droid is actually more convenient than updating apps from the play store, which I have to manually install.
There absolutely could be phone vendors selling LineageOS phones with F-Droid as the default app store. The only really important thing that would be missing for a lot of people would be WhatsApp.
On top of that, if you have a rooted phone, you can use F-Droid to automatically install updates. For me updating apps from F-Droid is actually more convenient than updating apps from the play store, which I have to manually install.
There absolutely could be phone vendors selling LineageOS phones with F-Droid as the default app store. The only really important thing that would be missing for a lot of people would be WhatsApp.