"Killing TurboTax" is essentially a meme until we meaningfully simplify the tax code. There is no software development team on earth who could catch up with the full capabilities of TurboTax without some sort of fundamental shift in the business. I really hate to say this as someone who makes a living out of it, but dealing with the current amount of complexity in the tax code with a piece of software that a non-expe…
I don't think this is much at all a technical problem. I suspect most people use TT because it's convenient--it files for you, they'll even pay themselves from your refund. And TT knows well this is a huge user base, as you'll see them hide away little features like education credits into the premium version.
I agree though that state taxes are part of the moat here, let alone municipal. In the few states I have experience though, state taxes are vastly simpler than federal. Still it'd be great to see some kind of centralized digital infrastructure that states could all normalize around instead of each building their janky web portals.