“Lifnim mishuras hadin” is unfortunately overused and misunderstood. A chumra which has no basis isn’t “Lifnim mishuras hadin”, it is stupidity. Somebody who sits in the succah while raining is called a ?????, not a ?????.
When the Chazon Ish saw people making Chumras which had no halachic basis, he would inform them they were wasting their time. They would reply, “Well, it can’t hurt!” He told them that he knew a man who would walk around with eye glasses that had no lenses in – just the frame. When people asked him whats the point, he would shrug – “Well, it can’t hurt!”