Freewheel vs cassette geared hub motors serviceability With ebike conversion kits there appears to be 2 types of rear hub motors: the ones that accept a cassette and a freewheel (see the image below from this aliexpress item)



Is the freewheel option more serviceable?

I mean when I'll be replacing the freewheel I'll be replacing worn out sprockets together with the ratchet mechanism.
Whereas with the cassette option the ratchet mechanism comes with the motor and I'll be only replacing sprockets and if there's a need to replace the ratchet then I'll have to replace the whole motor or is the freehub part with the ratchet that the cassette attaches to also replaceable?

Or is the freehub on the image above just screws on top of the freewheel attachment threads?
Whether the freehub rachet mechanism is servicable depends on the design of the hub. Nominally the pawls and teeth are separate steel parts in an aluminum hub body and therefore replaceable; but only if the hub manufacturer makes spare parts available.

Something else to consider is that the freehub version will be substantially stronger. The drive side bearing is further inboard on the freewheel version making the axle prone to bend or break.