Good catch on my poorly chosen wording. I can totally see how not using the word "illegal" changes the meaning of what I wrote, even if it was in direct reply to your reference to "illegal drugs".
That said, you seem to be implying that there would be no point in banning this or that type of gun,
partly because they would be available anyway, like, say cocaine or meth.
Except that we don't legalize cocaine or meth, even though the laws are not perfectly implemented and those drugs can still be found. The laws criminalizing possession and distribution of so-called "hard drugs" are thought to have value, despite not cutting of the supply 100%
So yes, if we
as a society decide to ban this or that type of firearm or accessory, they may still be available - just like illegal drugs. That is no justification to not ban such guns, after all, we continue to ban illegal drugs even though they remain available. There may, however, still be value - enormous value - in reducing the supply, just as with illegal drugs.