Not all software has to be hosted, require ongoing costs from devs, and thus be paid for.
Software can be provided for free as a public good by making it simple and local-first, but people seem to have forgotten.
@ActivityWatchIt is an example.
Thoughts on Omnivore shutting down:
Many people enjoyed Omnivore because it was free, but being free was part of its demise.
As an independent app maker, you must have a way to generate revenue or your product will die. As a user you must demand a way to pay makers for the products you love. See my essay: "Quality software deserves your hard‑earned cash"
I didn't personally use Omnivore, but it seems like many Obsidian users loved it. Now the app is being shut down with only a couple of weeks to export your data.
While this is abrupt, it isn't surprising. When a startup runs out of resources, the end is always more sudden than you expect. The dream of making it work persists until the very last moment.
A subset of people will find refuge in Omnivore's open source code, but the vast majority of users are not technical enough to compile/host/run a service like this.
In the end I keep coming back to the ephemerality of software. We have to appreciate that apps like Omnivore are being attempted. The apps that become self-sustaining will last longer than those that don't, but none will last forever.