How Reliable and User-Serviceable Are All the Fancy Electronic Stuff on Modern Bikes?

Do you just replace the ECU when the quickshifter, ride modes, traction control, etc. goes kaboom? Do they even go kaboom? Do the color screens go bad or get condensation? Are the sensors of the systems and such in the way of getting to stuff? Do the emissions stuff on the exhaust fail or cause problems? Things of that nature.

I'm looking to replace my two 2000's bikes. I've convinced myself to let go of analog rev gauges and to not barf at p-twins and triples, but I have to get over this last hurdle. I know anecdotal examples don't paint the whole picture, but I'd love to hear from the community.