Toxic Teams: Fight, Flight, or Hold Your Ground?

The answer is to leave the toxic team ASAP. A bit more nuance:

• If you're junior or mid-level, you don't have much ability to change the team culture so you should immediately leave.
• If you're senior (as you are), you have a bit more ability to change processes and people on the team. However, it stil is limited as an IC. There's probably an 80/20 rule here of some changes you can suggest or feedback you can deliver that address many of the problems. Once you've done that, just leave.
• If you're part of upper management, you may have inherited the problem and maybe even brough in to solve it. This is the case where you could consider the "fight" scenario if you have the power to make changes.

The world of tech is big and constantly getting bigger. Don't waste your time on a bad team or with a bad manager. Find another team, company, or start something on your own.

The last point I'll say is that there are likely some very smart + kind people on your team. Every team, no matter how dysfunctional, will have some people you jive with. As discussed in the networking course (The #1 Rule Of Networking), lead with kindness and build lasting relationships with these people.