I would only keep insurance if I felt clumsy enough to justify it. Most people don't and it's almost pure profit for the issuing company. I do have extended warranty on my paid off phone, though. That covers defects like the factory warranty, which I feel is justified due to phones seemingly becoming more prone to defects.
I played with my phones, so I had insurance on a Note 9 that I get replaced 3 times (once for free). But if you don't drop or lose it, it doesn't pay - unless it covers water damage and broken screens. (If you're in the rain and use your phone, you could kill it. If it's in your picket you could break the screen.)
Its subjective and up to the individual, but this is how I do it and how I recommended my customers at Verizon to do it.
Personally I recommend carrying it on a new phone or near new phone, the deductible is much cheaper than paying off the cost of the existing phone and financing a new replacement.
Once the phones paid for, I view it mostly as a waste. At that point most would rather finance a new phone instead of pay a deductible to have the old phone again.