Not understanding the bills is just one group of struggling paying their energy.
Many people struggling to pay for basic things like food, housing and utilities are actually really good with the numbers. They know which bills that can afford to ignore got a bit, which ones are really due and move around their debt. That's not ideal, but their reality and they will be on the best tariffs already (unless they live in rural Scotland where some are locked into bullshit 'totalheattotalcontrol-THTC tariffs, and don't have the cheaper suppliers available)
Unplugging things that are on standby are not going to help that group An increase in income will, or more affordable housing/energy will. It's the same category as the '20 pound shop- yellow sticker' advice.