We’re only seeing so much Rubick play because he survives the ban phase. So this begs the question: if Rubick is so dangerous, why isn’t he being instant banned? Because despite some teams being very successful with him, he is generally not worthy of a first round ban.
One reason for this may be that while Rubick is adaptable, he is not literally “game-altering” in the same sense other instant bans are. Ultimately he only has access to whatever you yourself bring to the table; he does not introduce a “new element” into match — he simply makes something in the match bidirectional. Comparatively, popular first round ban Furion fundamentally alters the gameplay of the entire match by creating the element of global presence absent without him.
Second is that while Rubick’s skill-set is very solid, he lacks an escape mechanism (unless he steals one). Since Rubick is generally not played as a support and is squishy due to being a spellcaster, many teams have adopted the strategy of shutting him down early to prevent him from becoming a threat.
Last is that he suffers from a “jack of all trades but master of none” syndrome. While Rubick can clone abilities, that does not necessarily make him a suitable substitute. He cannot simply be picked up in the event of the other team taking the hero you intended to draft. Some heroes are only effective because of the entirety of their skillsets. For example, Rubick will never be effective as an Invoker substitute because he can only grab one spell and what makes Invoker deadly is his ability to chain different situational spells. Spell Steal is most effective used against heroes defined by powerhouse ults, such as Tidehunter, Brewmaster, and Enigma. This makes him more of a situational pick that does not need to be banned preemptively. Moreover, in those games where he is drafted, stealing ultimates or other high value skills don’t ensure success. At best, keeping careful track of what ability Rubick has stolen allows you to counter Rubick the same way they would counter the base hero. At worst, all Rubick can do is unleash a tool that you yourself have.
Rubick is undoubtedly a sound hero, but he just doesn’t inspire the type of fear that heroes such as Lycanthrope can. Teams seem to have settled on being willing to both bet on Rubick and their ability to overcome him. With this equilibrium in place, Rubick is unlikely to fade into irrelevancy or become a common first round ban, and is sure to be sighted in the competitive scene for months to come."