If the French wish to have the rest of the world pronounce their language correctly they need to remove all those unnecessary letters. Worse than the English with their odd vowels popping up everywhere.
There's seriously no worse language than English when it comes to pronunciation! (Though I can only speak for European languages!) Even most (if not all) of my English professors at university would complain and make jokes about it. English pronunciation and spelling is a right mess, mostly because of the various influences the English language has had during its formation (French, Germanic (Norse), Latin)..
There are words which look easy enough and in my head (and embarrassingly out loudly) I pronounce them one way, thinking there can't be another, but nope! And the "right" way tends to not make much sense at times! This isn't even just a problem for foreigners, but also native speakers, which underlines the messiness of the English language...
French has indeed superfluous (ha!) letters, but once you get the hang of it, it's quite easy (and even logical I daresay!).
Other languages are even better, they are written phonetically so no confusion there, ever. Once you learn the alphabet, you can spell and read anything. (eg Slavonic languages are like this, some Romance languages like Italian and getting the hang of Spanish is also easy. Even Japanese pronunciation and reading (Latin letters) is dead easy (to me), I have read that Korean is also really easy (ie phonetic) as well).
I am only writing so much on this because I speak a few languages and am currently working on/ trying to learn and brush up on a couple more, so this topic has been quite ongoing in my head, sorry to write a whole novel!
(And also please don't take this as lecture or me taking your comment offensively or anything, just wanted to get it off my chest after days of thinking about this and this opportunity was the best which came my way )
Interesting question on why no one corrects French words.... I think the wrong pronunciation of "J Herbin" is just too ingrained and sounds quite French to a non-speaker, so no one bothers looking it up or correcting...
And it also seems like most people who are actually saying the brand name in a public way are not French speakers, eg I cannot think of one person who has a public channel about stationery, who is French (ignoring the French hobby community and just looking at English speaking channels/ influencers; that said I don't watch too many videos on the topic and don't listen to podcasts on the topic either, so my knowledge of influencers is rather limited, but those I know of are usually US American, British, Dutch..).