Personally, I would stop the dry food, except for a few (about half a dozen) scattered on top of the wet food. Cut down the amount of wet food gradually. You may find it helps to add water to the wet food, but only a little, otherwise your cat will no longer find it tasty.
One of my cats - Polly - has no teeth at all, and copes perfectly. How she lost them is a mystery. She sat on my lap and yawned, and I noticed she had no teeth!
It's more important to keep your cat's weight down. Being overweight will shorten its life and lessen its energy and playfulness.
Avoid treats for exercise, you'll negate the effect!
Maybe purchase a play-tower for while you're at work. When you're home and tired, I find those 'fishing rod' style of toy useful. (It's a long plastic rod with a string attached - they usually have a mouse or similar at the end, but I cut this off - you sit on sofa and flip the string from one side of room to another, puss chases it. BEWARE cats don't have much stamina, so only do this for a short time, they get puffed quickly.)