Are people going to make open source versions of these and maintain them and iterate till it's good enough to replace them or have their users switch over to the open version? It could happen, but it most likely won't. Software isn't dead.
I find most software has 90% more features than I need.
If i can take a 5% software and add the 5% i need, why would i not.
Theres certainly a ingrained value prop to everyone knowing excel, but if i just use it to twiddle the same formulas, then why do i need excel.
This basically sorts everyone into wizards or people without need if magic.
The idea that everyone needs to be a wizard was convenient SaaS sales tactic and business largesse.
AI allows more powerful wizards to enable better fit tailored software. It doesnot need to make everyone wizaeds. The same way excel never made everykne VBA programmers.