In addition, being the oldest running crypto-currency and with the larger market cap means that it was consistently attacked for years; it is the most battle tested and the safest in terms of technical hacking. It also has the largest processing power which means that a majority attack (51%) is not really feasible, incentive-wise.
Most altcoins (there are ~700 right now) have nothing new to offer. Some, however, do add new features. They have (maybe debatable) technological advantages over Bitcoin:
- Dash and the master-node layer with their innovative governance model
- Ethereum which allows complex smart contracts to be easily created
- Maidsafe, NXT, BitShares, ...
It is not easy to compare one on one these coins but Bitcoin is in no way superior technically speaking (and some times it can easily be considered worse!).
Technically speaking most innovations happen in altcoins since it is both:
- easier -- they don't have to support compatibility with the large infrastructure that Bitcoin has nor convince so many people for a change
- and safer -- not so much money at stake