I don't know much about the blockchain technology behind bitcoin to be honest.
However I have heard it is not without it's flaws - I've heard scaling and transaction speed to be two things. (The lightning network is going to speed things up i gather?)
Lightning is one of many 2nd layer solutions being used for payments with bitcoin. There will be other options and even 3rd layer solutions for payments over the next few years.
Seeing as Bitcoin was the first it'll always have that, and it is being updated with things like the lightning network and will likely receive many more updates over time, keeping it's edge.
But what is to stop another 'gold/value storage' coin with better technology than bitcoin taking over.?
Most answers I assume will entail: 1) it was the first 2) lots of people believe in it 3) limited supply cap.
Satoshi isnt involved in Bitcoin anymore now is he?
We know a Government wont create "better" bitcoin... why would a development team or a company create a "digital money" and somehow also make it fair for everyone ? That team of developers first need to convince all bitcoin holders it is better and more secure THEN convince people they dont have a motive to create a digital money for their own gains.
The size of a development team and amount of scaling solutions to compete with what bitcoin already has would be too difficult to "compete" with. Just join the "Sound Money" team that is on bitcoin and help that network grow...why would a competitor in money be a valuable spend of time, unless you are trying to create money you can rig....which wont work.
To top that It could have modern improvements that some of the other altcoins have these days - instant transactions and better scaling (no idea what that is btw) e.t.c.
Altcoins exist for OTHER reasons than to be money.
Altcoins that "run projects" like BAT token, could have used Bitcoin as money but they wanted to create a token, control the distribution and sale of that token. That lowers its value to a lot of people who are only interested in "sound money" like bitcoin offers. Nobody is claiming BAT token is like bitcoin but SOME people in altcoin trading threads seem to really believe BAT is like money....its nothing like money though.