I'd say 1/3rd is a rather large chunk of an SSDs TBW if its just for hibernating. In practice, for reasons you outlined, it would be a smaller amount but I would only find 1-2% tolerable.
I think this is less and less true as time goes on. I have a laptop from 5 ish years ago I still use and it's actually pretty fast.
And, even so, it's not like the ONLY wear on your SSD is the hibernation. So this 5 year figure, I'm not sure it's right. I think, maybe if you're someone who stresses your hard drives a lot (maybe you work with photography or videography?) hibernation might make an impactful difference.
For those with heavy I/O workloads, they likely have higher-grade or larger SSDs with a higher TBW rating.
Additionally, TBW isn’t a hard limit and can often be exceeded, with some drives lasting beyond 200%.
For most users, TBW won’t be an issue, and other components are more likely to fail before the drive wears out.