Ladies and Gynecologists

Please don't be rude idk who to ask.

I'm here to seek advice on tampons. I have heard so many theories and alot of mis-information on tampons. So i heard one today and I'd like to know if it's true. Ati if you use tampon long term( every time you have periods) you get foul smell eventually even if you're not menstruating?

While at it is there any downside of using them.