Well, after seeing the acquisition of GitHub by Microsoft - where people changed their VCS to GitLab or BitBucket - I believe people may replace npm to yarn. yarn is on the game since 2016 and in the past few years it has overlaped npm on usage, security and speed (as theirselves claims). Back in the day I remember to see those posts about "how yarn is faster than npm" or "how yarn is more secure than npm".
Competition always lead to improving services, and personally I see npm getting better and better as time time flies. Today, most people yet think about technology/tools itself, and not what you can do with them.
Today I don't see a huge difference between the managers, and I believe npm is on the rise of overlap yarn - Isaac said that npm's v7 (it's getting close!) and v8 are already being planned, and they'll be focused on experience and speed. So we can expect nice things on the move.
In 2020, I see a bright future for npm - talking about the startup and the service as well. 🎉