i don't argue that. It is just random IO isn't that important for our use case, especially compare to capacity and sequential IO which are important for us and which HDD is ok for.

Few SSDs can sustain such a speed for a long time. After they exhaust their temporary SLC cache they drop to much lower speeds. SSDs that have accumulated a large amount of writes might also make large pauses at random times during writing, for garbage collection. Good SSDs remain faster than HDDs even in these circumstances, but they are nevertheless much slower than when benchmarked for short times while they are new.