SSD longevity seems to be better than HDDs overall. The limiting factor is how many write cycles the SSD can handle, but in most cases the write endurance is so high that it’s unreachable by most home/NAS systems.
SSDs are however really bad for cold storage, as they will lose the charge stored in their cells if left unpowered too long. When the SSD is powered it will automatically refresh the cells in the background to ensure they don’t lose their charge.