Trout can be healthier than Salmon is but Trout is a member of the Salmon Family of fish so they can provide nearly the same health benefits of each other.
I like both Trout and Salmon but I mostly prefer to eat Trout as I find it also tastes better than Salmon but both are pretty good fish.
Fish including Trout and Salmon are considered healthy foods and also considered to be brain food which means that when you eat Trout and Salmon that your brain will usually be much healthier.
Eating fish is good for your brain and may also help prevent dementia and other mental health issues as you age.
Fish such as Salmon and Trout are high in Omega 3 which is also good for your heart health so eating all types of fish including Trout and Salmon may even prevent heart disease, heart attacks, strokes etc.