Sure, many positive developments may happen, but we should prepare for the likely possibility of not one of those things happening.
What if we don't find a cure and a vaccine takes 3 years?
Cheap, fast testing is almost there but I don't see how that actually helps... What do we do with people who didn't yet get the virus? Should they stay at home? Since they're a majority, it's not very different from the current situation. Or should they go out and "chance it"? Are you willing to do that in the absence of a cure?