APPLE CANT REPAIR THEIR OWN PRODUCT ?????????????????????????????

I took my Apple 6 Plus to Apple Dr. In Witbank after was send to a few people the technician said he can not repair the iPhone there is a problem with a motherboard that the reason for the sluggish unresponsive screen, i can throw the phone away? Is APPLE SO **** PRODUCT THAT YOU NEED TO THROW IT AWAY AFTER FEW YEARS I AM VERY DISAPPOINTED IN APPLE THINKING TO UPGRADE TO IPHONE 12 BUT WILL LOOK FOR OTHER MANUFACTURES