But it is just code at the end of the day. All code has flaws. This one demonstrates the whole 21M limit, which is the most fundamental piece that I can see, i.e. if no scarcity then what's the point, may not be what its made out to be.All your points are valid, but on a purely logistical level, attempting to "crack code" as you put it, on that scale for duplication is sufficiently more vigorous than doing so with the U.S Dollar for example, which currently justifies bitcoin as a hedge against inflation. The sheer amount of technological prowess, resources and skill needed for doing so is simply a barrier that the dollar doesn't have. That being said, theoretically there is no such thing as a perfectly invulnerable form of currency.
Someone didn't just happen upon this, they were looking. Fortunately a "good actor" found it.
In September 2018, an anonymous party discovered and reported an invalid-block denial-of-server vulnerability to developers of Bitcoin Core, Bitcoin ABC and Bitcoin Unlimited. Further analysis by bitcoin developers showed the issue could also allow the creation of blocks violating the 21 million coin limit and CVE-2018-17144 was assigned and the issue resolved.