Really it doesn't require a great deal of effort. I just finally convinced my Mum that her misplaced loyalty to her long standing 'big brand' providers was penalising her. An afternoon on the computer and I helped her switch her bank a/c, utilities, car & house insurance, phone & broadband saving her £1300/year in total plus a £125 cashback and a £100 M&S voucher. You are a fool if you don't at least check what you're paying every couple of years.
Agrre fully - I keep changing when I see an advantage and don't mind spending the time looking around - but have to be sharp to tell the firms that my direct debit is for this one deal only - not perpetual renewal.
It may be your experience that, for you, savings from switching gas and electricity aren't worth the hassle. But that is not the case for the average Briton. The CMA's competition investigation showed that 70% of households are on providers standard tariffs, and those people are paying on average £300 per year more than the cheapest tariffs
This is a huge amount of money for most people, and shouldn't be dismissed based on anecdotal evidence of one person.
You will have to check all the tariffs published - those that send you a bill monthly and also read your meter will rip you off. If you are careful and do the legwork yourself and pay by monthly direct debit and mindful of the conditions you can benefit. I just changed my electricity supplier after two years - with a significant price advantage. Will have to be careful next year to make sure the tariff stays.
Some insurers will replace a patch of carpet but not the whole thing - but usually the carpet matching yours is no longer made and thus a patch cannot be sourced. This is why I don't buy insurance on price alone - I look for firms with a reputation to keep.