I do not think that traditional British pubs are endangered. I don't think that they will risk being endangered as long as there are enough people who love them and care for them and continue to be customers. As long as there are loyal customers and fans, traditional British pubs will be fine.
Some pubs are dying, and some are changing. Though I haven't been to England, I have been to Ireland, and yes i know that'd be like saying you've been to America when you've just been to Canada. What I noticed in Ireland is that if people want a more traditional pub then they should go to smaller cities.
Traditional English (not British) pubs are far from endangered. Rural Britons pride themselves on a sense of history found nowhere else. The history of the place can be traced through pubs that have existed for hundreds of years. Traditional pubs in England aren't endangered because everyone loves the atmosphere, the food and the drinks. When adults want to hang out, they go to pubs.
No, traditional British pubs are not endangered, because they remain very popular. Traditional British pubs are not only popular in Britain, but they are popular in general all over the world. Going to a British pub is not just a place to go to drink, but it is also a place to go for an experience.
Traditional British pubs aren't necessarily in any danger, and they won't likely disappear anytime soon. Brits love their traditional pubs, and many of them are still quite popular. Other types of bars and pubs have popped up over the years, but they won't push the older establishmetns out of business in the near future.