Barclays do something similar in that the will pay you £7 for two direct debits for £3.50/m so you make £3.50/m, plus cash back at retailers etc.
As for your interest, as @NeilM made a very correct point, no risk no reward. People have all these systems to make on average maybe 2.5% (I believe its around this once you count for money in/out, regular savers etc.), but you can make that money just putting is in a an ETF or similar with a higher allocation of bonds etc. without the account juggling.
Savings accounts within banks are basically just convenience accounts to separate money. They’re very low interest bearing pots, and have been for a long time.
Keep in mind if you need anything more, cheques, cash, international payments etc. Monzo doesn’t do this, or they do it at a cost to you.
Monzo is a very basic bank still, make sure it actually fits your needs before switching.