Heh, well, it's (mostly) optional. You can buy a new bike off the showroom floor and ride it for years without ever updating anything or, really, even
using any of that new-fangled techno-electro-logical crap. :-)
Modern Harleys, however, have a lot of electronics available, if you want to take advantage of them. I've got a touch-screen unit that includes GPS (including turn-by-turn navigation), SiriusXM satellite radio, Bluetooth (for phone calls or playing the music on my iPhone through the bike's very well-equipped "Infotainment" system), a USB port (for updates and playing MP3s), a security system, a garage door opener, and so on. Other models might have CD players, CB radios, etc. The lower end/cheaper models typically don't have much more than a speedometer. Some of these are, easily, $50,000 bikes, though.
The software updates are dead simple, too. Download a file to a USB stick, plug it in, turn the ignition to accessory, and... wait. It shows the progress/status on the screen and takes maybe 10 minutes from start to finish. Someone like me (more "tech-y") usually gets the USB flash drive set up when an update comes out and then we all just pass it around when we get together for a ride or something. Others don't care and don't bother ever updating.
Even the "grumpy old-timey bikers" like their tunes. :-)