> When I imported Vert.x into my project because I needed to run a lot of non-blocking concurrent tasks, it required a lot of justification for using it instead

> When I imported Vert.x into my project because I needed to run a lot of non-blocking concurrent tasks, it required a lot of justification for using it instead of using threads everywhere. Isn't async unnecessary now? Threads are now cheap enough that its much easier to write sync'd calls on a thread.