Founders, what's your advice? (Facing culture/work issues at a startup) [I will not promote]

I work as an employee at a startup. It's a small team: ~15 people.

But here's the thing: the culture is in shambles.

1. People dissing each other behind the back (even dissing the founders)
2. Culture of fear: people afraid of suggesting improvements, correcting stuff that's horribly wrong, in fear of push backs and arguments (I'm talking arguments among employees, etc.).
3. No process or accountability. People entering or leaving the office whenever they feel like it.
4. Generally submitting shitty work.

Now, I know it's not my place to go out and try to change all this as an employee. It's the role of the founder.

So I'm thinking the obvious now: quiting and starting somewhere else.

Do you have any other suggestions? Things I could try before I finally start looking for new opportunities?

Because I can't work at such an environment for long.

[I will not promote]