The thing is those apps have not been competing with Autodesk or visa versa. Autodesk tried to go head to head with Side FX and lost. That was Softimage. Since then they have simply used those resources to develop MASH, Xgen and Cache playback in the viewport. A little improvement in animation workflow with sculpting for Blendhapes, and a few other small improvements. (not to mention the node features in Max).
But Side FX owns FX, Maxon -Mograph, and Modo, I don’t know - making shoe renders. Product advertising etc.
These are all niche markets. LightWave had a symbiotic relationship with all pipelines. That was its strength. And initially it had a niche market in TV FX.
We are not living in a world of diminishing choices. There have never been any good variety of choices for your basic go-to 3D app. That is how I see it. There was a brief moment in time when you had Max, Maya and Softimage. And a few stragglers hanging on to LightWave as an end to end solution. But it did not last. And apps started to specialize. Maya kept getting better at what it does which is animation and a little of everything. It is the only premere go-to app for all around 3D pipelines, worldwide, hands down.
The only app that has attracted the same kind of crowd looking for the app that could do everything reasonably well, over, say the past say 7 years, is Blender.
So I don’t think it matters what happens to those other apps. Maya has MASH and Xgen and Blender is getting Animation Nodes and Geometry Nodes.
Both Maya and Blender have reasonably user-friendly animation tools and overall attract the same kind of user base which is not a specialist base.
You want to open a shop to create general animation and fx that is strong on character animation and does everything else reasonably well, there is Maya and Blender. In my opinion, these are the only reasonable choices. If you want to do something the other apps do well at, likely you go there.
If any of the other apps fail, kind of a 50/50 split. Some users will fall on Blender and others on Maya.