Sounds like you were in a gnarly situation and did well to get out. You are what you do, and those types of places can have a long-term corrupting influence on your professional habits and instincts.
The observation that “all companies have politics” is about as useful as the observation that both Venezuela and Denmark have imperfect governments. These statements are correct only in the narrowest sense.
Those pointing out that you never work for “yourself” are also technically correct. If you own a business, you have a responsibility toward your customers. The good news is that it’s possible to find a niche in which you actually like your customers and enjoy doing right by them. Running your own company also gives you the opportunity to optimize for what you think is important, both personally and professionally.
Best of luck.