Hi @Sharon Nityashri Fried - I'd recommend just using credit card rewards, for multiple reasons.
1) You won't get taxed for the same amount of money you get back.
2) Having to use debit cards instead of credit cards is fairly dangerous. If someone magnetically swipes your card, it's a lot more troublesome to revert debit transactions than credit card transactions.
3) 1-5% in credit card rewards is no the same as "cash back" -- it's a lot better than cash back. 1-5% can translate to 10-20% in value back per dollar spent. And if you'll spend money on travel anyway, you'll always get to use those points. The most extreme example is Chase Sapphire Reserve: You get 10X points on Lyft rides, and a $12K USD first class plane ticket is redeemed with 120K points. In this extreme case, $1 spent on Lyft rides is a free dollar on a first class plane ticket (i.e. +100% value).
But if you don't travel or have a lot of credit card expenses, why not do a high-interest savings account? Their interests are surely going to beat a high-interest checking account and its purpose is more akin to what you're looking for: lower requirements for transactions.