Apple

I'm all for it when there's a monopoly. Microsoft has so much market share that them restricting access to the PCs would be anticompetitive.

Apple is closer to half. And they built the market share they do have with the closed ecosystem because that's what people want. I don't want apps to be able to require me to give them my credit card. Subscriptions through Apple are extremely user friendly (even if subscriptions inherently are shit). Cancelling is easy and not buried in dark patterns like every single company that handles their own subscriptions does. "You have to follow our interface guidelines to sell your product on our phone" has massively increased the quality of the apps on my phone. Android is an incoherent mess of bad design because you can do whatever you want, and the experience is worse for it. Whether they recognize it or not, most people are buying Apple because of the pattern of decisions they've made as the sole standard setter for products on their platforms.