I believe it is a very personal choice. First of all which product is the most comfortable.
The silicon cups is not a new thing at all and from my personal point of view the best one, there is a wide choice (not all of the companies are sustainable but for example Organic Cup do a lot social responsibility programs), but some people are allergic to silicon. If the person likes pads, reusable pads might be an option, and period underwear during that time gives confort as well. But there are some tampons which are eco friendly too, totally plastic free (expensive)
The period cup lasts years, you don't need lots of recourses to take care about it, it is very economical, it is enough to have just one item.
These days sucks, so it is important to have the best comfort.