There's no assurance that bitcoin will stay on top, but we have a lot of good altcoins and I believe crypto world will continue to exist in the future. For now, we have to support what is very popular and valuable and that is bitcoin.
Yeah i couldn't agree more with you and the simplest ways to keep supports bitcoin is stay use bitcoin until future. If there is still people enthusiasts with bitcoin , bitcoin will keep exists until the future. That actions is easy ways for bitcoin users to keep supports bitcoin as well.
I think that every time the Bitcoin can have fall in value, there would be ideas such as this one that Bitcoin would one day die and be gone for good. Well, no one can be sure of what can happen in the future but I do hope that Bitcoin will stay alongside with the top fiat money we have. I don't see Bitcoin to completely replace the fiat money though.