Go back to the 50’s and 60’s (think that era is correct) and you would get punished in school for speaking Welsh. There was a thing called a Welsh knot which was used for striking children with if they spoke Welsh. This almost killed the language I believe.
During my school years we were taught Welsh, but only as a second language unless you went to a Welsh school. The language is now having a resurgence amongst younger people who are taught to Be proud of their language and are encouraged to use it more. Personally I think this is a good thing, it’s the native tongue of Britain and it would be a huge shame if it were lost forever.