Baby still eating purée meals

I need help. My son is not interested in whole solids. I try all the time and he just spits it out. I believe it’s texture issue or he’s lazy to chew. He eats dry things without a problem such as crackers, rice cakes, raisins, veggie straws, toast, pancakes.

I’ve tried making him sandwiches and “hiding” an extremely thin slice of meat and cheese but he didn’t like it. I’ve tried veggie muffins didn’t want that. He’s 15 months and should be trying to use a spoon but we’re going backwards. I just want him to eat like other babies. In the end I just give him purée bc he needs something in his tummy