If we follow that logic, you could say “stropping is not necessary just after honing the razor”… how can a strop improve a 30K edge?
However after the first (or any) shave the edge of every razor is deformed with fold-overs and chips… this is where the strop will better the hone any day.
The strop gently straightens those fold-overs and will polish the insides of chips restoring the edge as good as before.
The hone on the other hand can only remove material to get back a shaving edge.
Stropping will prolong the life of the razor.