Ab exercises do help strengthen and stabilize your core muscles, but it's important to distinguish they don’t selectively burn fat. Theoretically, you could knock out 1,000 crunches a day and that wouldn't guarantee belly fat loss.
When it comes to long-term changes to body composition, your total energy expenditure (calories burned) compared to your total caloric intake plays a much more foundational role. Overall, find ways to exercise that feel consistent, doable, and enjoyable, and take things from there.