Is assembly worth learning in 2018?

Answer 1

you need to understand it if you program at hardware level. doesn't matter it is 2018, new hardware, drivers and compilers still have to evolve and get better, someone has to do it.

Answer 2

Yes, it will help you to understand what are behind the scenes of all high level programming languages such as how memory allocated, how functions are called, how different control structures such as if else, switch, while... really work at the lowest level, what some errors like stack or heap overflow, or some other cryptic error mesages showed sometime mean...
These things are quite helpful when you debugging your programs.
My suggestion is that if you have free time study assembly for a few weeks, just enough to get the hang of it, and then move on to other language.
You will rarelly use the language in the future, but basic concepts will benefit you.