The American Dental Association has a webpage on toothbrushing recommendations. I don’t see any reference to “hard bristles bad”.
Personally, I do not like soft mooshy toothbrushes. I use a firm brush and do a reasonable job without scouring. I have never gotten scolding at the dentist for rubbing off enamel.
It is difficult to find hard bristle toothbrushes these days, possibly because Americans are weenies.
It’s not a matter of my listening. In the vast body of dental research, you’d find your E laughed at. For hard bristles to get even a fraction of the cleaning depth of soft ones, you have to inflict gum-tearing effort and will get poorer inter-tooth cleaning.
Ask any competent dentist - they’ll show it to you with little models and everything, and back it with any level of research you care to follow. “Hard bristles clean better” is a counterproductive, if not somewhat dangerous (to your tooth longevity) folk myth.
I suspect hard-bristle users have gotten completely intolerant of even slight tartar build-up and don’t feel like their teeth are clean unless it’s scoured off the tongue surfaces. If you’re prone to tartar build-up, the only solution is more frequent professional cleaning. There is no home substitute.
The public documents from places like the ADA are always going to focus on basics like “brushing good, not brushing bad” and omit (by committee-think) anything that might discourage people from doing the right thing. If you dig deeper you’ll find information about toothbrush approval and statements about how harder bristles are not approved unless specific testing shows them to be non-damaging… which is not the same thing as recommended. A more general search will turn up plentiful expert advice to avoid harder toothbrushes, and why.
It has nothing to do with rubbing off enamel - even floor brushes are far too soft to damage enamel. It’s about gum damage, which is the reason people lose teeth even after a lifetime of reasonably good oral care.
Water pick is the bomb. Good for your gums also.
Also, “floss, dammit!”
Oh, yes, please do. No, brushing is not enough. And yes, I can smell your rancid mouth sewage from across my desk.
That’s what I use them for. Restocked my supply last week.