I suspect most grids are extremely easy to hack(never tried, don't bite the hand that feed you etc).
Info sec is just a hobby of mine. I install high voltage switch gear for a living.
I’d expect the opposite. All companies controlling equipment that is part of the “Bulk Electric System” have to be NERC CIP compliant and are audited regularly with large fines for non-compliance. Doesn't guarantee perfect (or even good security) but it’s more likely to be a priority.
A fine is a black eye for a utility where people pride themselves on the reliability of the service they provide
Until there's some kind of hold-harmless agreement, the various industry & government security information sharing groups can only be of limited effectiveness.