Asbestos may be - but no cigarette bud I have ever seen has decomposed. So definitely none of the millions I’ve had to see has ever been made of organic materials. And I would have a hard time believing that I simply never saw an organic cigarette bud in an intermediate decomposition stage. So they haven’t been used in any significant amount during my lifetime.
I have on many occasions cleaned up the discarded cigarettes stubs of some inconsiderate shithead smoker, yes. But even without that, unless you live in Singapore, you should have enough awareness about whats going on around you to notice a pattern after a couple of years that you never see cigarette stubs in any form of decomposition, only the fibers coming apart.