Nope, all PCs came with Windows and OEMs willing to sell alternative computers didn't had volume discounts.

It was a choice, but most decided to cave in and only sell PCs.

Here that isn't the case, most shops selling iPhones also have other brands available. Customers aren't forced into buying iPhones.

You raised the bar that is required. It is more appropriate to look whether iPhones are a dominant brand, not whether they are the only brand.

Which they are not.

As it turns out, they are. [1]

[1] https://www.statista.com/statistics/266572/market-share-held...

You have 45% phones to chose from.

That's another switch of the goal posts. Clearly, any brand with 50% or more is considered dominant.

Not at all, we are still talking about choice, and clearly the law decides how it goes, not random Apple haters on HN.