What about the problem of osmosis that boats with composite hulls can suffer from, if land based blades only have a finite life then in the harsher conditions this lifespan can be reduced. Then we have gearbox issues,composites do not "rust"
https://www.htlgroup.com/general/why-do-turbine-gearboxes-fail/
Now maybe these could be solved if they used a fluid coupling but who knows, changing a gearbox offshore is more involved but the cost is around £500K.
Now battery storage would resolve many current problems when we have no wind but could we ever reach the point where you could run most of the uk from just batteries for say a few days until the wind picked up, we are talking of Giga watts per hour !
What we really need to do is build only energy efficient homes that require very little energy to keep warm with more than just 230 volt circuits. All the lighting could be low voltage and run directly from a low voltage circuit which would easily be achieved with solar tiles on the roof and a local battery backup, now think of the reduction in demand if a large percentage of homes did not use the grid for lighting.