With respect, that's complete and utter horse shit.
Many independent venues have faced closure in recent years but almost never down to a lack of custom. Things like landlords hiking rents to attract more lucrative commercial tenants, business rates going up, and the increasing difficulty for small independent licensed premises to turn a profit are contributing factors.
Nobody is making a penny out of socially-distant gigs. At all. A lot of it - and I had three last weekend of my own - is propped up by CRF grants at the moment.