Hello and welcome to the forum. We have a thread on feeding the fussy dog here.
Dogs are attracted to food by aroma so you are right in the steps you have already taken.
Wet food tends to be more aromatic and fussy dogs sometimes do better on it. With regards to the fat/fibre in such foods they do tend to have a higher fat level (dry weight) than dry food. This shouldn't be a problem as long as the correct amount is given. Also, dogs do need a reasonable amount of fat in their diet, especially young, active ones. The lower fibre content can easily be rectified by the addition of well cooked brown rice or oatmeal. Cooked, mashed sweet potato is also a good option. For dogs who are full quite quickly a good quality product can be advantageous so it might be helpful to look for something with a high nutritional score. If there is more than one variety in the range, that might be useful.
As your dog is of a good weight then he is probably getting what he needs. Small, more frequent meals may be helpful - perhaps three times a day instead of two. Try to give them at quiet times when he is calm and has nothing better to do. If he doesn't eat up, just remove the bowl and try again later. Try not to get anxious about it because dogs are very quick to pick up on human emotions.
Just a thought - if he wears a collar in the house, make sure the tag isn't hitting the bowl as he is eating. The noise can irritate some dogs.
Sometimes fussy dogs can be tempted by enhancing the diet with some human, cooked food diet - link.
Edit: There are now a few fresh foods available but they tend to be more expensive. Freshpet can be bought in some supermarkets. Butternut Box and Different Dog are subscription based - they are delivered frozen. Fussy dogs often do well on such products. We Cook for Dogs is a business that assist the pet owner to home cook for their pet. They sell the necessary supplements and provide suitable recipes. You will find more information on the forum about these by using the search box.