Static weight on the top of the turbine matters very little. The overwhelming load consideration for a turbine is air pressure on the blades. That increases tremendously while they are spinning and harvesting power.
Direct drive generators with rare earth magnets are preferred offshore because of lower maintenance and improved efficiency, but in fact are *heavier* than induction. Induction motors use a gear box that is prone to wearing out but allows for a much smaller, lighter, faster spinning generator. it's right there on Wikipedia.
Most rare earths are not that rare just messy to extract, concentrate and purify, but once we have the material it will be recycled forever. The sooner we have that Nd in spinning magnets the sooner we are displacing carbon heavy generation sources. North sea offshore wind is a no brainer, especially considering the limited local solar resources from cloudy conditions and high latitude.