One of the Mac’s greatest long-term advantages has been the ease of attaching external monitors. The attachment connector type, resolutions supported, and total quantity has varied over time, but it’s a persistently easy task. Or at least it was! Over the last six years, Apple introduced USB 3 over USB-C (12-inch MacBook, now discontinued), Thunderbolt 3, which uses USB-C (and supports many kinds of adapters), and the Apple silicon M-series processor models. Some Macs have or still include video-specific connectors, too: in the past, that included DVI (multiple forms), Mini DisplayPort, Displa…