My mum still drinks posh versions of Bovril, i.e. beef tea, albeit extremely rarely and she is in her 70s. I am not aware of anyone younger who does.
One thing I must note about the UK that fascinates me - maybe it's true of all countries/places, I dunno but... - is how much fast food and restaurants - and sweets, actually - have changed over even the relatively short time I've been alive (I'm 47).
For example, when I was a kid, in the 1980s, we got all sorts of Americana, with a lot of restaurants loosely based on American 1950s diner nostalgia stuff and serving a lot of burgers (which linked to general 1980s nostalgia for the 1950s). By the 2000s, those were mostly gone, and by the 2010s, if you wanted a burger, it was likely going to have to be a "smashburger" or some ghastly microwaved-seeming pub thing (which I would, perhaps unfairly, also file "Honest Burger" and that similar one under). Used to be back in my day < snaps suspenders, leans back noisily in chair > you could get a malt vanilla milk shake reet easy. That was true up until about 2015 (in part because "smashburger" places initially brought it back) Nowadays though, good luck getting any milkshake which isn't bad chocolate, bad vanilla, or "bad vanilla but with some kind of overly-sweet chocolate bar/biscuit blendered into it".
Or we could look at the rise of the mighty "chicken shop" (i.e. place dedicated primarily to selling fried breaded chicken), going from barely existing in the 1980s, to pretty common by the early 2000s, but super-super-declasse, like you normalized towards "urban working class" a huge amount just by stepping inside one. And those tended to be independent and on-off, or regional-specific brands like Morleys. And now it's become not only not-declasse, but so mainstream and typical that smug middle-class middle-managers might take people there for a "team lunch". Indeed, this is so obvious even the often culture-oblivious BBC News wrote about it recently -
How US fried chicken craze is transforming British takeaways - of course the BBC acts like this is some recent thing, not a gradual change over the last 20+ years because they're run by people so hopelessly middle-class they'd catch fire if they stepped over the threshold of a Morleys. Also amazingly manage to get the name of one of the brands wrong (it's Slim Chickens, like the country musician Slim Pickens, not "Slim's Chicken", you culturally and functionally illiterate dimwits!).
