Most of the alts are completely useless and not much beyond a pump and dump. There is a long history of dead coins that proves that. A few have real world applications but something truely special will have to happen to take down bitcoin at this point.
Yes other alts have better tech than btc, but the best tech doesn't always win out. It's just whatever the people decided to adopt, and btc has been adopted enough that it's probably going to be around for a long time to come still. I believe something else will replace it eventually, but not anytime soon.