This is the model I want from 90% of the software out there, just give me a reasonable price to buy it, make the product good, and don't marry it to the cloud so much that its unusable w/out it.
There are also a lot of added benefits to this model in general beyond the data privacy (most are mentioned in the article), but not all the problems are solved here. This is a big space that still needs a lot of tooling to make things really easy going but the tech to do it is there.
Finally, the best part (IMHO) about local-first software is it brings back a much healthier incentive structure - you're not monetizing via ads or tracking users or maxing "engagement" - you're just building a product and getting paid for how good it is. To me it feels like its software that actually serves the user.