Besides Photo Supreme, what are these photo apps you speak of. I may be interested.
Canto Cumulus: https://www.canto.com
Extensis Portfolio: https://www.extensis.com/portfolio
Cumulus asks that you call for pricing and Extensis is quoted at $300/per user/per year
Isn't the benefits of buying Apple because of their "ecosystem". Isn't the photos app part of the "ecosystem". Haven't I already paid for the "ecosystem". Doesn't apple want a good "ecosystem"?
Yes but you're confusing ecosystem with only apps made by Apple. If you stick to only Apple apps your computing experience will be fairly basic. The ecosystem is broader and more sophisticated than that. Apple give away a lot of free apps and they all have the same thing in common: they're 'good-enough-for-most-things'. So, Pages is pretty good if you're making a newsletter or writing letters. Want to layout a doctoral thesis? Not so much. Then what do you do? You go into the 3rd party market and buy more powerful apps, like Word, Mellel or Nisus Writer. Ditto with Numbers and apps like Excel. Same with iMovie and Photos. (Though in the case of iMovie Apple also sells a pro level app.) That's the ecosystem: a space where Apple give away free mid range apps to their users, but also leave space in the ecosystem for 3rd party developers to create and sell. That's a good ecosystem, a world of Apple and 3rd party developers offering power and choice to users.
When I got my Mac I was willing to buy Aperture. Apple killed it off.
Hardly relevant here in that Aperture didn't support the library on a network share either. But look at the ecosystem now around Photos - and this is not even including apps that work as extensions to Photos - you have Adobe Lightroom, Adobe Lightroom Classic, CaptureOne, Exposure X6, OnOne PhotoRaw, DxO PhotoLab, PhotoSupreme. That's 7 apps off the top of my head from 6 different developers. They have different capabilities and work at different price points. That's a healthy ecosystem. That's actually more diverse than the ecosystem around word processors! And each of those apps is a photo manager, we've not even got close to editors there.
And - with the exception of Photo Supreme, created and maintained by one guy, and the cloud version of Lightroom which has the library in the Cloud, and so is not germane to this discussion - what do those apps have in common? None of them support the library on an NAS either. What they might do is support storing masters on the NAS and having the library on your internal disk. (This is theoretically possible with Photos but I would not go there in a month of Sundays - an absolute recipe for disaster.)
When photos was working on my hard drive connected to AirPort Extreme I used to open the app up quite often and look at photos or go get one when I needed. I can tell after using Mac without this ability I will use photos barely ever, only to save new photos and never view again.
I'm not sure I understand your point here. You'll collect new photographs but never look at them? Huh? Why bother collecting them then?
And this:
Also, TV and Music libraries are still on network.
Don't you see the enormous difference between these libraries and the Photos one? The TV and Music libraries are about as complex as an address book. You don't edit files with either of them. Photos, on the other hand, does the same things as these apps do (create albums/playlists/edit metadata) but also manages a non-destructive editing process built around a parametric editor, along with the integration with many other apps and extensions. It really is a far more complex beast.