From my limited experience, they're good at offering an enticing savings rate but a year or two later will whack it down close to nil. They're playing the same game as utilities and insurance, after a year or two your benefits shrink or your costs go up.

Examples, had a 2% interest rate "ISA"-like account and it went down to 0.01%. Home insurance doubles in 10 years through lack of changing it.

Switching all our services yearly is a time suck and they know it.