Resilience - turns out you can't just put a one word answer.
Edit - actually let's answer your misconceptions.
No SSD's don't inherently address all things, they're quicker yes, that's it - we still need resilience. I've been using PCI-based storage for nearly a decade (FusionIO) but always in R1 as we need the resilience.
Seek time isn't actually zero, page table changes still take time, not long but they do.
Lifespan really is NOT 'much longer' - in fact in many scenarios they're STILL worse.
And some systems, especially when misconfigured, can make SSDs slower - but not if the right products are combined and people do their homework.
Also SATA/SAS SSDs are pretty much over - for laptops/desktops you should be buying M.2 PCIe-based storage and for top-end/commercial kit you should be buying NVMe kit - SSDs have had their best days, move on.