It's not the "strength of the brand", it's a brand name that should have never been allowed in the first place because of that kind of confusion, that's specially why they went with that name, they knew, it is market manipulation, for the same reason Phone is not allowed as a phone brand
There's a difference between whether a name is sufficiently distinguished to trademark and whether it is prohibited as "market manipulation." One certainly could not trademark the word "phone," but it would be perfectly legal to sell a phone branded as such.
...and? Yes, there's a difference, but Peloton isn't just selling "peloton bikes," they've trademarked the name Peloton. Unless you are agreeing that a phone company named "Phone" would be as bad as a company named "Peloton"
That brand is only known in few US states, the world refer to peloton as https://en.wikipedia.org/wiki/Peloton