@Jojobees @TheIncredibleBookEatingManchot
my understanding (happy to be corrected!) Is that it's the lack of indepth bsl provision to a high standard
There are courses that get you up to a certain level eg gcse but that's not enough to be an interpreter. In the same way I couldn't use my gcse French to be an interpreter, and would need much further study beyond degree level, but also likely a period of immersion. There's a difference between people being able to get by and then able to interpret legal documents and medical appts
Often French or Arabic interpreters for example are native speakers, with English as a second language learnt from a young age. They often speak it fluently after periods of living abroad, or family immersion. There's a much smaller cohort of that experience for bsl (remembering that a huge portion of even the deaf population don't use it fluently).
Getting that standard is tricky with bsl, and would need people to be educated beyond degree level to fluency which is very time consuming and expensive so far beyond what most people at an adult education center for example can provide
There's also a shortage of teachers. Our interpreter was explaining that lots of courses are actually taught with a fairly poor standard fluency from the teacher eg the person teaching level one might only speak it to gcse level themselves
So once you get past a certain point there are very few teachers
This is my wild assumption point:
I've rarely seen English as first language, british born with british parents interpreters for other languages. When I booked an interpreter for my first language over here, it's someone connected from my culture that comes. In reverse you rarely see the English interpreters in other countries actually being British, it's often people from that culture with a good standard of English.
I think that's just harder to find because bsl is solely taught in this country , so all intepreters have to be from here. Out of the deaf population bsl isn't completely universal yet, so there's very few people growing up and living in households where it's spoken and lots of the people that use it constantly are deaf themselves and you can't lip read in a paid interpretering situation like you can in day to day life. Combined with my belief that the uk doesn't tend to develop interpreters