Sure, for small projects. Otherwise, you'd better have a solid plan in place for keeping your business logic in a common core, otherwise you'll just be writing N separate implementations where N = number of target platforms.
Even in a world of agents, less code = better code.
Sure, I hear this (with current models). But consider the UX complexity of a typical TUI. Even with a TUI framework, you end up with serious coding lifts just to get things that the all the current native UI frameworks give you for free.