Scalability problems is the main problem that bitcoin will face if the community will decide to accept segwit. I am not against segwit but there are just some things that segwit needs to settle before they can start with bitcoin and that I say is the problem on scalability. Bitcoin unlimited on the other hand is nice but there are many errors and bugs and so it is much safer to stick with segwit as long as they can find a way to settle the problem on scalability.
Xester, thank you but it sounds to me that you are saying everything you mentioned has a problem?
The proven option with least problems and the solution to the world's money/store of value problem is and has always been bitcoin.
Though bitcoins has been facing many problems and almost all solutions being provided have also many loopholes but it will not stop bitcoin from striving and developing itself. Bitcoin will remain stronger than ever and the secret behind that is the support of the community and users. Without the support of people who patronize bitcoin over other cryptocurrencies it would already be dead by now.