Same for my last job. My bosses and managers harassed and insulted me. They said I was useless and stupid.
I quit with 3 months of "notice" (standard in France to help you find a new job). They didn’t care during those 3 months. In the last week they panicked because they could not find a replacement that did everything I fixed every day.
I also interviewed my replacement, a junior out of school with big diplomas. When I asked if he knew Linux, he said "not really." I thought "they are fucked with this guy." They wanted to hire him because he was the son of some guy. I said to my boss that he would be a perfect fit for the company.
Unknowingly I was the kill switch. I sent them one last email with all the information they needed and told them to go fuck themselves in a polite way.
They can take the salary of the CEO to fund the browser, they can ask for donations that go directly to the browser, they can make subscriptions with useful services. So many ideas that they didn't try in the past 10 years. But it's easier to get free money from Google and do nothing.