Partially. Inverters providing virtual inertia is good but has the problem of still being active and reactive. It helps and is cheaper and more efficient than flywheels.

Flywheels and turbines however provide a very sticky frequency. They help out a lot with stability and give inverters time to respond.

Think balancing a stick on your hand vs anchoring it in clay.

If we take enough turbines off line we are still probably going to need some mechanical power stabilization no matter how inefficient.

But yeah I think we are going to see a blend using as much electrical and as little mechanical as possible.