Looking at software more specifically the Linux foundation reported based on software dev salaries in 2008 it would be 1.4 billion to only write the Linux kernel.
Up until about 2023 there wasn’t enough money involved to have any reason to make a real CUDA killer even if you could get it adopted.
Replacing CUDA with another framework has much lower motivation. That advantages of the new framework must cover the switching costs and the risk of such a switch. All while CUDA continues to evolve and allow access to additional features.
Apple and Microsoft had something of a captive userbase. New vendor on the block trying to replace CUDA does not.
And the people they were selling that to, ( It's free and open souce now! ), were a very different group to the market they left behind on .NET Framework, who are often still struggling to make the transition now.
Had they actually killed off .NET Framework, it would have been a different story, much more like the VB6/VBA to VB.NET transition, which so few people bothered with that VB.NET died out, because if you had to retrain that much, you figured you might as well go to C# or a instead, or indeed a completely different language entirely.
I briefly worked professionally on a VB.NET project, but outside that job I've never met anyone else who can say the same. I've met a few who went straight from VB6 to C# though.
Largely the same market (Enterprise) but not the different segment (web as opposed to Windows/WinForms).
I ported about 15 years of projects from various versions of .Net to .Net Core whilst they were developing (and sent feedback to the team - they were asking us to do that) and the process was pretty reasonable. You were only really stuck if you were using something very very Windows specific (certain image processing libraries iirc) and even then it was largely manageable.
The old full-fat framework is, AFAIK, still supported, as there's a whole lot of legacy code which is Windows specific which is still expensive / hard to port over.
Between MSMQ, WCF over named pipes, MSDTC, and MSI installers, there's a lot to replace that is hard to provide the same guarantees or performance with straight replacements, if they even exist.
The end goal, being on modern dotnet, is better, but it's difficult to get there with a phased approach without accepting a temporary worsening, which is often hard to sell.
Especially while Framework is still supported.
I was under the impression that AI was supposed to remove software-moats, let us all ask it to write our custom MS Word for us for instance?