I'd quibble with that. Capitalism is a choice, market dynamics are not. E.g. The Soviet Union successfully outlawed capitalism, and in response market dynamics made their country collapse.
Unregulated market dynamics also gave us child labor, slave trade, 12h work days, company scrip, companies ruling over governments, etc. A powerful engine without constraints is out of control.
England imposed the institution of slavery on the American colonies by means of their regulation of economic affairs. It didn't occur spontaneously from market dynamics, but was specifically provided for by (their) laws.
I think you're missing the forest for the trees. The slave trade existed as an institution for economic reasons, and for thousands of years before England was a nation. If it were unprofitable then people would've stopped doing it, regardless of how it started.
It wasn't just some government flex.
You also haven't addressed any of the other negatives that unregulated market dynamics have manifested.
England literally supplied the early American (and later Australian) colonies with slaves "indentured for the term of their natural lives".
The "American colonies" were, of course, not limited to the modern USofA; Sir John Hawkins of Plymouth aka "the Pioneer of the English Slave Trade". formed a slave-trading syndicate in 1554.
He sailed with three ships for the Caribbean via Sierra Leone, hijacked a Portuguese slave ship and sold the 300 slaves from it in Santo Domingo. During a second voyage in 1564, his crew captured 400 Africans and sold them at Rio de la Hacha in present-day Colombia, making a 60% profit for his financiers.
Saying England implies in a way implies that the colonists in the Thirteen Colonies were in any way less complicit for making slavery widespread in the North American colonies. They were mostly autonomous and self regulating and chose to adopt the institution of slavery. They could have just treated the black slaves the same way as white indentured servants.
Caribbean colonies were of course quite different.
I don't think there's much meaning in saying the Soviets outlawed capitalism.
Capital continued to exist and there continued to be people who decided what got built and who received them. To me, that's private ownership. I mean, it's not like apple trees suddenly began bearing Ladas. If I wanted to acquire a field to occupy / farm, it was presumably controlled by someone, either an individual person or group of people. I don't see the difference in saying that in one situation my neighbor owns the field as personal real estate, versus whatever terminology the soviets used for why I can't just take it.
> there continued to be people who decided what got built
The distinguishing feature of capitalism is that the people who decide what gets built are private individuals in competition with each other, and incentivised by profit to meet the demands of consumers.
In communism the people who decide what gets built are part of a single central authority with no competitors and no profit motive. That system doesn't work, which is why it collapsed.
Plus, an important aspect of capitalism is that the employer/employee relationship is freely entered into or exited from on both sides. In communism, that typically isn't the case.