> But why subscription for local-only software?

I assume that they decided the business model and user experience separately. It's generally harder to build local-only software than stuff that just uses the cloud for all the hard work, but it's a better user experience. I'd be willing to pay more for local-first, but yeah it certainly does feel weird.

There’s still currently the need of a server to synchronise data between Allume clients (Mac + iPad + iPhone companion app), but it is completely useable offline on one device. Adam Wulf, the now solo developer of it, mentioned that a local P2P sync is in the pipeline.

Developers deserve to be paid for their work. Adam's work on Allume is ongoing, so he deserves ongoing income.

Seems like a subset of LiquidText

https://www.liquidtext.net is more PDF-focused, but the workspace is cool.