I feel that direct ab work is an unnecessary thing unless you have a weak core.
However, the squat and deadlift are both great core strength exercises. If those exercises are increasing then it’s very unlikely that your core is not getting stronger with it!
So I’m not against direct core work, but I’m also not a big fan of it. I think a lot of people “sell” the idea of core exercises because people related them to having abs. Abs are a product of the diet moreso than training…and with training you want strength…which is usually targeted through heavy compound movements.