I got mine (Ultegra Di2) in May 2014 and it is still going strong. I've worn out chains, cassettes, and even the chainrings, thanks to a combination of on and off-road riding with loads of hill climbing. All of the Di2 stuff is as solid as the day I bought the bike. Since Di2 hasn't been around for 10 years (as far as I am aware), I can only extrapolate, but it isn't showing any signs of problems. Batteries have a finite number of charge cycles, but so far I have no indication of any battery issue either.