Relax, it's a myth: https://www.pcworld.com/article/2925173/debunked-your-ssd-wont-lose-data-if-left-unplugged-after-all.html
On the other hand, I won't trust the SSD to archive data. Always make a HDD backup of your important files. But please don't use a 10-year old HDD from your old laptop as a backup drive either..
