Congrats on landing a FAANG position! As long as the environment isn't toxic, you can find a way to be content.
Use this as an opportunity to learn how to adjust your thinking so you can thrive personally in a challenging environment. You may never get to a point where you love it, but you can probably get to a place where you are successful and can focus on the positives.
Learn how to work well with challenging people. You'll encounter more of them later in your career. Again, adjust your thinking. These people almost certainly have their positive qualities. Work with those positive qualities and become a master at mitigating or avoiding their bad qualities.
As far as working nights and weekend goes... do you really have to do that? Are other team members doing that? Big companies are not like startups. All the things will never get fixed, and you simply need to do your best with things in a permanently semi-broken state.
I understand that you don't want to coast. You don't have to even if others are. Focus on doing an excellent job on your corner of the world. Your projects, your code, helping others, etc.. Worry less about the bigger picture.
Also remember that it's not forever. This is an investment in your future career.