Given honest participants acting in good faith, self-interest aligns with common good. You start a business that provides value and does it sustainably with care about the environment; I recognize that and support your business by being your customer and maybe investing in your company; you profit, I get the value, everyone benefits.
Now, speculative investment, information asymmetry, short-term gain seeking, etc. kind of ruin the idea.
It's all about how you define self-interest and whether your pursuit of self-interest is so short-sighted that it's effectively suicidal; which is what the trend has been. I think it's best to drop the term capitalism all together.
It doesn't require anything remotely close to total selflessness, just not abusing the market and abiding by its spirit would be enough.
Sadly, the way many individuals and entities act is why the totalitarian straightjacket of zero-trust approaches a la “blockchain and reputation points for everything” seems appealing to some (not that I think it would help).
Now, speculative investment, information asymmetry, short-term gain seeking, etc. kind of ruin the idea.