But even half an hour isn’t a long walk. ;)
It’s also a route I’ve done often, hence how I know.
And if you cannot find an art gallery, auditorium nor cinema in Soho then you’re doing something very wrong.
There is a theatre at Tottenham Court Road. It is over 30 minutes away from the Barbican centre by foot (but about 10 minutes by Elizabeth line).
The nearest major art gallery to TCR is not in Soho, but 15-20 minutes from Tottenham Court Road. There are two other major galleries closer to the Barbican than anywhere near Soho. Both are at least 25 minutes by foot and at least 25 minutes by tube.
There isn't an auditorium in Soho, unless you can name one? St-Martin-in-the-fields is no closer than the National portrait gallery, 20 min by foot or 15 by bus from TCR. Easily 25-30 minutes from the Barbican centre by any means of transport.
Likewise there are several repertory cinemas in Soho but none of them are 0 minutes from Tottenham Court Road.
Your claim of 15 minutes by foot was completely laughable. My claim of around 30 minutes in each case was accurate.
In theory Leicester Square is a 15 minute drive. In practice you'd have to be mad to drive yourself but you could Uber it.