Capitalism is a game where only a few people get to win.
We have also seen time and time again that it is a game that is able to manipulate and change whatever ideology or behaviour you have to work towards its own benefit.
So the only way to actually "win" is to not play the game.
Right now that seems impossible because it is a massive collective action problem, however this whole platform is a testament to show that it's possible to overcome that kind of problem.
Reddit is a dominant platform that is starting to destroy itself. People are in turn finding alternatives such as Lemmy to satisfy the need that Reddit once did.
I view capitalism in the same way. It will never truly completely cease to exist (the same way Digg never truly died), but it can become irrelevant over time if we collectively decide to just use another system to satisfy the same needs that capitalism is satisfying today.
The one example that I can think of that tries to tackle this problem is the idea of free stores that are based on a gift economy. If more people decided to use this system instead of capitalism then capitalism will have less sway over people's lives.
And in the end it doesn't have to be specifically a free store that needs to be adopted by wider society but whatever it is does need to satisfy the same basic need that capitalism does in our current society.
Boycotting is an expected/intended tool in capitalism. It's part of the "free market" philosophy, the regulatory "invisible hand". The reason you can boycott a company is because the economy is based on a capitalist free market.
If boycotts were actually a good and successful method for the society to regulate the wealthy, then there would be no issue with capitalism. So that's not how you "end" capitalism, that's just how you make it work.
The issue is, precisely, that boycotts do not work (and thus, capitalism does not really work). Particularly when entire industries are controlled by private de-facto monopolies. If they worked you would not need social-democratic laws to force companies into compliance in many ethical aspects.
What you are advocating is not an alternative to capitalism (like communism or socialism), but a more ethical/educated capitalism that works at controlling the wealthy, just like many proponents of capitalism expected it would.
You are talking about boycotting businesses. I am talking about boycotting individuals out of economic and social participation. Making them unable to exist as they do within a society, through fear of inconvenience, or social ostracization, or other things.
And yes, there is never going to be one magic silver bullet for billionaires. That's why I listed that among other means to deal with them. As I said, it's about making it too detrimental for them to choose to be that.
That's even harder. Specially if we aspire to have a community that protects privacy & anonymity.
Keep in mind "rich" does not necessarily mean "famous".
For all anyone knows, you and me could be part of the wealthy, yet nobody here would know, no online service would deny us service. Being forced to live an anonymous and private life is not really much of a punishment, at least it wouldn't be for me... if I were part of that wealthy I'd just lay low.. I'd get a reasonably humble but comfortable house in a reasonably neighborhood where people mind their own business, dressing modestly and living life without having to "really" work a day of my life, while my companies / assets / investments keep making money so I can go on modest trips and have some nice hobbies that are not necessarily really that expensive anyway. Anyone who figures it out, I set them up. It'd still be worth it to live that life.
Wealth without any kind of external indicators is 1) not generally a problem, and 2) are not generally the actual wealthy who are causing harm.
Are there millionaires who live in a 500k house and drive a Mini? Sure. But they're going to be on the low end of millionaires, not generally in the Capitalist class, just in the higher end of trades.
No one is out to deny people a comfortable house, modest vacations, and hobbies.
People are trying to solve for the kind of wealth that buys political power, or that can upend communities, or that has legislative sway.
Bezos cannot be anonymous, and still have the influence he does. Or Musk. Or even just the executives of publicly-traded companies. Anonymity is something that wealthy people have a hard time with.
The reason that most mid-level millionaires can be anonymous now, is because no one is intent on finding them all. It's not hard to if you're out to do it.