Installed it and played around for a bit. Nice work overall. Amp's jump mode (press `f` and elements in the buffer will be prefixed with a two character jump token) is pretty cool. Would love to see this in Vim.
Some other commenters in the thread have raised the point that having more supported functionality out of the box is a good selling feature. To me it seems that having it built it can (possibly) benefit from a more intentional effort to make it cohesive, whereas with many disparate plugins you have to encourage, force, or otherwise guide developers to build something that fits and behaves with the rest of the platform.
For editing text, there's already a lot of flexibility in Amp's keymap system[0]. As users compose more sophisticated/useful macros, we can promote them to the default keymap, and if they're really useful, we can build them as discrete commands in Amp itself. That way, the core editor evolves to encourage a particular workflow. It's opinionated, and it may not appeal to everyone, but that's kind of the point.