Saying socialism is a form of capitalism is...unconventional. I think very few people would agree. Personally I see socialism as something that can be blended with capitalism, but doing so results in a less capitalist system. And when I see someone advocate for capitalism, I assume they mean the mostly unregulated kind like you see in the US, and which is forced in a lot of poor countries under the guise of "economic development".

I consider myself a socialist so I guess we're not as far apart as it seemed at first.

But anyway, the point I was originally trying to make is more general: the best system might not even exist yet. In medieval Europe they thought feudalism was as good as it got, and ideas like capitalism and socialism hasn't been invented.