that was the primary purpose before, but since .NET Framework will no longer be implementing new .NET Standard versions, it's now more like a way to write something that runs on both .NET Core and on Xamarin platforms
.NET Framework 4.8 won't implement .NET Standard 2.1 doesn't mean .NET Framework won't implement new .NET Standard versions.
.NET Framework has been announced previously to be slower-movinh and lower-risk than Core, so it's not surprising that it will take longer for it to support new versions of .NET Standard. That the next Framework release won't incorporate the newest Standard doesn't mean Framework won't advance it's Standard support going forward.
The "slower" explanation doesn't really fit with that sentence to me... if Standard 2.1 already has things that Framework "cannot" have, then it seems like "stopped" is more accurate than "slower." I guess technically they only are saying that Core gets things Framework can't, not necessarily the standard, but I'm not sure that's much of a distinction in practice.
Of course it doesn't have to mean that Framework is just frozen but it would seem to make the Standard a bit of a dead letter (I'm not really familiar with how useful it is in terms of Xamarin/Mono/Unity).
Yeah, I think the question is "will Framework be the slow moving, but 'living' component you target for long-term, but perhaps not eternal, stability on Windows platforms or will it be a legacy component that Windows is burdened with only for backward compatibility with older apps".
I think Microsoft has sent signals out which point in each of those directions, but not yet converged clearly on one or the other.
It would be great if they better articulated that "probably not ever", but I can't blame them for not doing that when we all know that a bunch of enterprise devs and HN/Reddit/Slashdot randoms would be out in force with pitchforks and torches if they did.