This is where V1G beats V2G.
V1G (AKA grid-adaptive charging) just chooses when to charge the car, to efficiently spread out the grid load overnight and spatially across the network. No extra charge cycles, in fact it's probably more mild than just charging at full speed.
The key is that you need a UI setting for "Immediately charge to X%" and "Charge to Y% by Z:00." This avoids the problem where you find yourself without enough charge to get to work (or the local hospital).
> you will now see multiple 0%-100% charge cycles daily.
Even for V2G, why wouldn't there be a depth of discharge slider?
> if its lifetime will be shortened... then electric company need to compensate owners
Or better yet, owners set their car to only "bid" for a grid storage job when the cost-per-kWh is greater than the cost of degradation.
This should be the default after enabling V2G.