If I believed that, I wouldn't get out of bed every day. A large part of choosing action (activism, startups, remodeling, etc) is suspending disbelief.
I have friends working on single payer. I just attended a policy planning event last night. To your point, the outlook is pretty bleak.
I give money. I've also decided to also give time and labor.
Meanwhile, I've come up with a Plan B, a way to hack the current system to expand affordable coverage. Early feedback from my policy and industry friends has been very positive (which is a novel experience for me).
1. Healthcare is a luxury that must be earned. Giving it away to people who don’t deserve it is categorically bad.
2. Jobs are important. Universal healthcare would mean fewer people working in the various health industry bureaucracies, which is categorically bad.
3. Business is important. Universal healthcare would kill or cripple health insurance business which is categorically bad.