There's an incredible range of options out there, all looking to serve different kinds of users. I thought about all of these things while I tested every macOS to-do list app I could get my hands on.
That disrupts your workflow, which defeats the entire point of productivity software. Applications that don't feel like they were designed for macOS are distracting because things like keyboard shortcuts, notifications, and menus don't work the way they do in other applications. They, perhaps more than users of any other platform, are picky and expect things to look and work a certain way.
And it's particularly hard to make Mac users happy.