We got such a grant a few years ago and shaved a few thousand dollars on strengthening the crawlspace under our California Ranch. It was already bolted to the foundation; this process strengthened the posts and beams supporting the frame.
If you live in an older home with a soft story (like a parking garage, storage or commercial space), retrofitting and/or insurance could make a lot of sense. Earthquakes can cause soft storys to collapse, as witnessed in the 1989 Loma Prieta earthquake. It didn't help that the San Francisco structures in the Marina district, built literally on Bay mud, were liquified by the ground movement.
So the land the structure sits on is important too. Our soft story apartment building at the time of the '89 quake, on San Francisco's Russian Hill, was built on bedrock. We had a few hairline cracks in the plaster walls, but that was it.
$30 million in grant funding slated for seismic retrofits were cancelled, part of the $3 billion in BRIC grants (Building Resilient Infrastructure and Communities) created under the Biden administration. I imagine a lot of this money would have helped homeowners in areas prone to flood, tornado and hurricane damage too.
I don't have earthquake insurance. Hoping I can make through another 10-12 years, after which I sell the property.