When mine was young I only gave him dry food. Then he developed kidney disease (CKD) 4 years ago. It and diabetes are fairly common in older cats.
Now he gets dry food plus wet food in the morning and evening - 1/2 of a little can or 1/4 of a bigger can at each feeding. The dry food and wet food are in separate bowls. That plus finding a water fountain he likes has so far kept his kidney disease from getting any worse.
Next cat I’ll give wet and dry food from the start.