Supply and demand. We’ve not been training enough tradesmen for 2 or 3 decades, they’re retiring and there’s nor enough coming through to replace them.
Costs are increasing - van costs, fuel and repairs, insurance, accountancy, phone contracts, materials, bank charges, etc.
They have to price in all the non chargeable time of travelling, quotes, picking up supplies, admin, holiday time off, etc, waiting for deliveries etc.
Also more awareness to look after themselves and prepare for years to come, I.e. paying into pensions like employers have to do, sickness and health insurance to cover if they’re too ill to work, life insurance to cover their dependants, gym membership to stay fit, etc. They don’t accept a life of work till you die anymore! They don’t have an employer to pay for it all, and growing realisation that governments won’t provide enough support, so the cost has to be borne by the customer!