Yes, Yes, but No.
Yes, it will shorted the lifespan of the SSD. But even modern budget SSDs can easily support writes of 50GB (or more) per day, 365 days per year for 5 years or more. So defragging a SSD will NOT shorten the lifespan of the SSD in any way you will ever notice, unless you do it many times per day, every day for many years.
Yes, manufacturers say don't defrag but that is because it is not needed due to the way data is stored on SSDs (see my mail sorting box image in post
#104 above).
No, it is safe to defrag a SSD, just a waste of time.
I agree with Roger_M. While that blogger may know his stuff, he is wrong in what he said. I didn't bother to watch the second video because his first 15 second video was just wrong. If a computer is 20 years old or older, that means it was made in 1998 or before. XP came out in 2001 and even XP computer hard drives needed defragging. So did W98 and before. And those versions of Windows did NOT automatically defrag the drives. So he was wrong to advise against it.
Just because a "talking head" is popular, that does not mean what he or she says is always right.