It's really hard to imagine anything else than a Bitcoin standard as a replacement, despite many people claiming it's old and clumsy technology - such people don't really understand the economics behind lt. Bitcoin already has the track record of unchangeable monetary policy and forks won't be able to compete because Bitcoin has the network effect going for it and most processing power behind it. It's already close to a miracle that it managed to emerge organically and stay decentralized, so a better version cannot be engineered from topdown, like everyone is trying. Other projects should focus doing another niche very well instead of competing in store of value.