Many countries that have
invested heavily into offshore
have done so either because land
is a premium or the geography
makes in difficult to buil
on land.
The Netherlands is investing heavily in offshore wind, and last I looked it's not those reasons, but NIMBYs.The cost per kW for offshore wind is higher, and even in a country as dense as The Netherlands the footprint of a windmill is relatively trivial, and can be combined with farming etc.
But people don't like how they look and sound, so we're paying a premium to have wind installed offshore.