In the last two decades, various Acts have been passed to ensure that, in Wales, Welsh and English are both official languages, and must be treated equally. These were the The Welsh Language Act 1993, The Government of Wales Act 1998, and The National Assembly for Wales (Official Languages) Act 2012.
The view expressed in this thread that Welsh should be confined to history horrifies me, seeming to hark back to previous centuries, when Welsh children were made to wear the "Welsh Not" if they were caught speaking their own language whilst at school. This was a heavy wooden board that was hung from a rope around their neck. Sounds pretty barbaric, doesn't it?
In the face of such a concerted attempt to eradicate a population's own language, it is a testament to the determination of the Welsh that they did not allow this to happen - and that the speaking of Welsh has increased in recent years.
Welsh is considered to be an older language than English with some written texts dating from the sixth century, but - like all languages, including English - it has inevitably picked up words and phrases from other languages over time. It is through such changes that languages stay dynamic and evolving, and English also contains many words borrowed from other languages.
I have never yet met a Welsh person who could not also speak English, and growing up bilingual is an advantage, anyway, as it makes the learning of additional languages easier. I speak four languages (and also learned Latin), and there is no-one in my family with a poor grasp of English which would "hold them back" in terms of gaining employment.
They are all well able to express themselves in English, as are all the other Welsh people I know. They may not choose to do so if they are in the company of other Welsh speakers - but is there any reason why they should, as long as they are not excluding any non-Welsh speakers in the group?
I am also not at all sure about the concept of "necessary" or "unnecessary" languages. If those criteria were applied - especially given how well much of the rest of the world speaks English - then many, many languages might be deemed superfluous. And yet, of course, they are not, as indigenous languages have a far wider significance than just as a means of communication.
I hope that Welsh children will always be encouraged to learn and speak their own language, as I would hope that children in other countries around the world will always be encouraged to use theirs. Indeed, I rather wish that we Brits could speak the languages of other nations as well as we expect them to speak ours!
It never ceases to surprise me when relatively-young children in even the poorer parts of the world speak English so well, despite the fact that they use their own languages within their tribes or communities.
On that basis, I might be tempted to argue that those who speak several languages are more highly-skilled than those who don't - and are therefore far from being "unable to communicate"!
But Welsh isn't just a literal language just studied or used on road signs. It is a language used every day by people of all ages. With successful Welsh TV the language is flourishing in a society where English dominates. A certain level of Welsh is expected by employers today, and speakers and non-speakers take pride in the language.