[Bloody Sam Roberts]

If you own an SSD there is simply no point in worrying about fragmented files as those disks can access their storage randomly. Where traditional hard drives access sequentially.
Defragging your SSD will only increase the read/write count and thus reduce the lifetime of your disk.

[Johnny Diamond]

If it’s unnecessary why does windows 10 do a trim on the ssd then?

as far as lifespan, they are rated to withstand 100gb a day writes (typically) for the warranty period (3 to 5 years). Even if you defrag an ssd once a week I would bet that your ssd would outlast every other component on your computer except for maybe the ram.