[goldinfra]

My sense is that you probably could help them get their technical act together, if the team was otherwise in good shape, but that you're probably not the right person to provide the kind of comprehensive leadership they need.

What's required to fix this situation is for someone to manage up and down the hierarchy, and it doesn't seem like you're going to be able to pull that off in this organization. Maybe someone with more experience could make it happen but it's probably just a shitty company and it's not worth the effort.

The fact that the CTO and directors let this situation fester for years is a sign that they're clueless and/or disinterested.

Best alternative would probably to create a new team to replace the previous team's services one-by-one with well-operated versions. And then fire the previous team entirely. Probably not a very fun job.

If you have better options, take them. I would.