Forged iron or grill : AskCulinary

I feel like whenever I see restaurants or chefs cook a steak it’s never on a grill and always done in a cast iron and an oven. I get this is probably for searing and basting with different pan ingredients but I cook on a salt block and get the sear from that. Other than that fact, is there any other reason one would cook with cast iron and oven instead of a grill???