Cash

One thing I will say, is that I think any shop/cafe/venue etc that only accepts either one or the other, should clearly state as much before the customer reaches the point of sale.

Theatres do generally state card-only in a welcome email, but how many people read those in detail?

If you book online, theatres do tell you if it's cashless or not, cinemas is 50/50 as some do and some don't. 

There are cons of being cash only as you need to hire a security firm to transport money to banks. Of course, if you're a small business then perhaps you or someone else can do it for you but generally speaking, if you're making lots of money per week then you wouldn't just be cash only. 

Weirdly while I mostly use card for payments, I still have an Oyster card which I top up every couple of week even though it's easier to use to card or contactless. 

Those figures from Barclays need to be taken with a generous pinch of salt.

80.1% of 85 to 95 year olds don't do their own shopping, so goodness knows how they're managing to use contactless so often!?!

Yes, and those in their 80s who are mobile enough to go out shopping for themselves are capable of tapping a card, so those figures don't surprise me.