The point of division of labor (aka how civilization got built) is that it's not _necessary_ to spend time re-doing the same thing others are doing. Slack is giving you something for free that you don't _have_ to spend time or money building now.
Now you have X engineers free to work on something actually innovative, not just a clone of X, and getting a cheap/free service from slack.
The point of economic policy should not be to produce pointless jobs.