I miss the times when all the phone companies their own own chargers and connectors (this was before USB charging). It was nice because I could charge my phone at my friends, because they all also had Nokia's.
I miss the times when different camera brands used different types of memory cards. My favorite was xD, not because it would have been any better than the competitors, but because it was more expensive and had a funny name.
I miss the times when all the camera brands had different lens mounts. The best brands had several proprietary mounts: Canon simultaneously produced lenses for three different digital mounts. Canon was the king. When universal lens mount was adopted in 2035, innovation died.
<sarcasm ends>
Many things have been unified over the years, such as currencies in Europe. In general Euro has been a success, but it's actually quite difficult to evaluate the full effect, as things get complicated. It's not just how the banknotes look, currency affects whole economies.
When it comes to memory cards, lens mounts or power connectors, evaluating the value of diversity is much easier, as they are only supposed to one or two relatively simple things. The shape and name of these things is really not important. What matters is that the less the better.
