Why didn’t my dogwood bloom?
We do not see any disease or insect issues. However we can see a cultural/environmental issue which could be stressing the tree.
Mulch should not be piled on, or even touch the bark, at the base of a tree. (Think about a woods. Nothing on the base of trees.) Mulch should be back a few inches from the tree's flare (where it widens as it goes into the ground). Mulch should also not be more than 2-3" deep.
When you pull the mulch back, be sure that you can see the tree's flare. Tree trunks do not normally go straight into the soil, but they can be planted too deeply or settle deeper after planting. Being planted to deeply will slowly kill them.
That said, dogwoods also have been known to flower abundantly one year and then take off a year or two.
Other reasons that trees have been stressed lately has been too much water. Standing water or constantly soggy soil has killed many trees in the past two years.