We're pretty much still building the tools to build the software renaissance.

It's here already, but not at a global scale.

You can pick any application you pay for, but only use 10% of the features of, and create a bespoke version that only has that 10% in it. It'll take you a day to get an MVP and maybe a week or two for it to be "good enough".

I thought about doing that with Todoist.. and then just decided I'd rather pay the $4-5/mo or whatever to not have to use unpolished apps and sync server

Why would you do that though if 10% of the other software is better?