In nost cases it’s more a question of “What is the risk if I do this myself?” and “If I completely fuck this up, is it going to cost more to fix than just calling someone who knows what they’re doing before that happens?”
If the answer to the above doesn’t involve a fire in my walls or serious water damage like with electical or plumbing, and the cost to fix mistakes is low, then sure, I’ll try it myself first.