Thanks for the update Bruno. Sorry to hear about the difficult situation, you have my best wishes that it improves quickly!
I'm having a go at updating the VTK and Paraview packages myself.
So far it seems many of the existing Arch-specific patches have been upstreamed, which is nice.
It also seems that VTK now requires the "verdict" package, which is only in AUR, so this is a complication.
I assume "verdict" will have to be included into "Community" - fortunately it's an extremely simple PKGBUILD.
If I am able to to make VTK 9.2.6. and Paraview 5.11.0 compile from updated PKGBUILDs on my machine, I will get back to you.