There are only 2 ways to make Bitcoin scalable and fungible:
1. You upgrade Bitcoin with the best tech out there, accept the tradeoffs
2. You use other networks that tokenize bitcoin, such as Beam/DarkFi/Zano. You get the features for BTC, but don’t use the Bitcoin network
But a popular number 3 is:
You pretend that the problems don’t exist, Bitcoin is already perfect and it’s the fault of users for wanting to use Bitcoin or having greater expectations from it