The difference to me is that if I’m locked into using one particular email provider because I don’t feel like going through the hassle of updating all my accounts, it’s a low inconvenience, since most email providers are free/relatively cheap. But if I’m locked into the Apple ecosystem for the same reason, it’s a much bigger inconvenience, given the high cost of their hardware and privacy/security concerns (which some email providers also have, but that’s an issue in both cases so it’s moot)