Bitcoin is money / a store of value, people are not going to abandon their wealth only to jump onto a hypothetical better money / SoV just because a better technology has come along. If there are technological innovations that allow for a better money, they will be implemented as a layer on top of Bitcoin rather than creating a new unit of account from scratch.

Bitcoin may be a 'dinosaur', but it's a bit like wine, the older the better. It has stood the test of time, it's decentralized etc. The base layer's sluggishness is its advantage. Also, decentralization is a process, you may create a better technology but to make it decentralized takes time. And the network effect comes into play.

Look at TCP/IP. It's not the best protocol we could possibly come up with for the purpose it serves, but the entire internet runs on it and no one is proposing to move away from it; we just build on top of it, because "if it ain't broken, don't fix it". And it's not even a fair comparison, because it's easier to switch to a different network protocol than it is to switch to a new SoV, as there is no generational wealth at stake. It would be very difficult to replace Bitcoin, much harder than it is for Bitcoin to replace fiat, because Bitcoin is a huge milestone that solves many problems in a grand, monumental way; something slightly better than Bitcoin wouldn't be a huge milestone and yet you'd still have the hurdles of initial insufficient centralization, lack of adoption, lack of battle-testedness etc. to overcome. Bitcoin has gone through hacks, blocksize wars, splits within the community, regulatory attacks etc. and withstood them, which makes it stronger. Any successor of it would have to do the same; so it would have to be better not only as a technology, but also as a network, which is hard to achieve, because generally a better technology is more complex, but Bitcoin's strength also comes from its simplicity.