HDMI is a somewhat-open-ish, widespread standard and for what it's worth Apple MacBook models haven't carried HDMI ports for ages now.

> Why are dSLR cameras allowed to continue to use micro USB and SD cards when they could just use USB-C so we don't have to buy dongles and adapters?

Again, the market seems to converge towards USB-C already (almost all the models on [1] and other buying guides have USB-C), and for memory cards towards SD cards and CFexpress (on the pro segment). Both of these are somewhat-open-ish again.

The EU usually only steps in when the free market is either stuck somewhere along the road and needs a push towards a specific standard (=> USB-C), profit incentives need to be overruled (=> RoHS / leaded solder) or the free market suffers from oligopolies that need to be broken up for actual competition or the creation of an actual single market (=> EU-wide mobile roaming).

> The argument that Apple only provides one physical port (they also provide Magsafe and allow other wireless charging options) isn't sufficient with respect to your discussion point about market-wide standards.

Apple can provide a MagSafe port on MacBooks or a Lightning port on iDevices if they want. All Apple has to do is to support the mandated USB-C port as well!

[1] https://www.digitalcameraworld.com/buying-guides/the-best-mi...