No, it's not always possible to found a new company. There are financial and temporal problems, and most markets are increasingly controlled by monopolies, which small companies can't compete against.If people are free, they can always found a new, a better company, and reject the evil enterprise. Also, if people are free, they can stop buying stuff from the evil company. If someone controls all, the system is not free. If people are free, they can walk away from exploiters.
Sometimes The Evil Company is the only game in town, and if exploiters were easy to walk away from, they wouldn't be able to exploit.
If you want healthcare, or medications, or university education, or housing, or internet, or phone service, in the US, you're going to pay exorbitant prices, because government has been decimated, and no longer does its job. Corporations have cornered the market.
If you want electricity, or want to drive, you have little choice but support the polluters, and pay their prices.. It's a captive market.Pollution is perhaps more difficult question, because tyrants of our time can define normal breathing as pollution. But, also in this case, I think best way is that people are free and if they think someone produces stuff in a bad way, they just don't buy it. That is very democratic way to decide what is good, when people vote with their own money.
You want to put up eco-friendly solar panels on your roof in Hawaii? Good luck. Hawaii's power market is entirely privatized, and you will be heavily penalized for any attempt to circumvent it. Hawaii's solar industry has been pretty much shut down.
And how about Pacific Gas and Electric; another privatized monopoly?
PG&E had taken 100 million earmarked for safety upgrades, and distributed it to senior executives."PG&E knew for years its lines could spark wildfires, and didn't fix them." -- Wall Street journal. July 10, 2019.
The Camp fire destroyed 14,000 homes and killed 85.
There was ENRON, and the crash of 2008. You can't evade it. The tyrants control markets, employment and opportunity. Government, the only entity with the power to regulate this, has been emasculated.