Depends on what it is and what it offers. If the product is something unlikely to experience failure that would be covered(like a standard, basic Weber grill), then no. If it is and there are no additional offerings for registering, then no. I keep photo copies of my receipts so there is never a question about purchase dates or warranty expiration. If there are additional offerings, I weigh the need for them and if they are good enough then yes, I will.

I’ll add to this that I always buy the insurance anytime it’s offered. I accidentally bought it with a TV about a decade ago and two days after the warranty expired I was moving and dropped the TV(barely. It was about an inch from the floor an shouldn’t have had a failure from the drop). It would give audio but no video. I told them that and they still replaced it, free of charge, with a much better model. My electric shaver just died two and a half years after I bought it and used it every day: replaced for free with a better model. The insurances have paid for themselves at this point.