Tampons are made out of cotton and rayon, and for that reason and they take much longer than toilet paper to break down (six months). Flushing tampons or pads down the toilet bowl can block up some toilets (flushing pads in particular is very risky). Most public
toilets have a special bin for sanitary products within every toilet stall, and a sign telling women not to flush their sanitary products down the toilet.
Although public toilets advise against flushing tampons, most toilets today can easily handle tampons being flushed down them. I would guess that most women flush their tampons down the toilet when they are in a bathroom that does not have a sanitary bin. That is what I do at home when I use tampons, and I know that my mother has been flushing her tampons down the toilet for thirty years (while living in six different houses) & has never had a problem. Most modern plumbing systems can handle tampons being flushed down them.
A few years ago I worked as a cleaner at a small 5-star hotel. There were no signs in the ensuite bathrooms to warn guests to not flush sanitary products down the toilets. Unfortunately there were also no rubbish bins in the bathrooms (although the adjoining bedrooms had rubbish bins). One day a toilet in one of the ensuite bathrooms began overfilling after a female guest flushed a tampon down the toilet. The water spilled out of the toilet bowl and started to flood the rest of the ensuite bathroom and the adjoining bedroom. The guest was embarrassed & very apologetic -I felt really sorry for her. The guest and her partner stood around as another cleaner and I tried to mop up the bathroom floor. When the plumber arrived the toilet got fixed & the couple paid for the cost of the plumber.