Several years ago we opened a high-yield savings account with Citizen's Access, a fully-online bank. (It's affiliated with a brick-and-mortar bank, though, and it's FDIC insured.) At the time, the rate was 2.5%. We put most of our savings there, and then bought two five-year CDs at 3.5%. Over the first couple of years, the savings interest rate kept decreasing, reaching a low of 0.4% before rebounding. (Still a ton better than our credit union, but disappointing.) The current rate on the savings account is 4.75%.
Our Chase Visa card has 1% cash back on every purchase, and 5% on select purchases. The "select" category rotates every three months. In the summer, it's gasoline purchases. If you take your refund in form other than cash (Amazon gift card, etc.), then you get more money than the points would indicate.
If you're interested in safe long-term investments, think about an I-Bond. https://keilfp.com/blogpodcast/i-bond-rate-november-2022-may-2023/