Cups of tea in cafes. It’s a tea bag in some hot water. £2.50???
42p of that is VAT which goes to the government.
Don't you want someone to make it for you and clean up after you? Staff are expensive.
Don't you want somewhere to drink it? A chair to sit on and a table? A room to drink it in? Rates, water, insurance, power, security, waste disposal, bank charges, property maintenance - all very expensive.
Most small cafes don't even make their owners a living wage!