It is mostly dependent on Chrome development. Chrome is supporting Catalina and higher and Netflix works on HS and Mojave with a hack for now, but the browser will not be updated anymore so they will be gone at some point. I am sure Gecko browsers are in the same shoes.
Safari which uses Silverlight will not play Netflix because Netflix ended support for Silverlight on September 13, 2023. Only newer versions of Safari sans silverlight will work.
I opened a case with Netflix and the support told me to update the OS. I told them about their website and they replied that they're probably gonna fix it.
Now they did.
You can use Netflix on computers with Windows 10 or later, macOS 10.15.5 or later, or Chrome OS version 76 or later. You can also watch on iPads with iPadOS 14 or later using Safari and some Linux computers.
help.netflix.com
Still stupid. I installed Fedora and now it works. I know most people don't care, but the machines are obviously still perfectly capable.
It is not about the machine but the OS restriction.
All these machines can run Windows and Linux and most probably Netflix and the other sites/services requiring DRM.
I know, that's my point. I totally get why it can't be supported forever, but it is quite unnecessary to retire a machine just because its discontinued software support.