I think many, like myself, will concede this point. Harden is a genius at "hacking" basketball. I don't really complain that what Harden does is traveling as much as the traveling rule needs updating so that it is.
If you go to YouTube and type in “FIBA gather step”, you’ll see a video released by the rules body showing legal 0 steps, the rule is being used exactly as intended, to the point where they want people to know it’s explicitly legal.
What you don’t notice is that the gather step is used for many more movements other than a euro step, but the euro step also has a change of direction and change of acceleration that combine to make the movement look illegal to someone who doesn’t understand the rules.