Why? Time and I/O speed isn't as relevant for everyone as you might think. I sure don't want a system without flash memory, but I know not everybody is me and not everybody will care.
I cloned the drive onto an external SSD with no other changes. Immediately she had a usable machine, and she now enjoys using it again.
That does mean OS/DE devs are hitting disk way the hell too often and just hoping modern disk speed makes it harder to notice, but there's no way that's not adding up to some real (but less crippling) latency even on SSD-equipped systems.