MiscroSD as a cold storage/backup drive

Hey everyone,

I travel a lot and I have 2TB SSD and a 2TB HDD and most important documents backed up into cloud as a 3rd spot.

I want to unload the 2TB HDD backup with something lighter if possible and looked into MicroSD cards.

I’ve often read about MicroSD being less reliable than other storages but I did some reading and I came up with a plan and want to pass it by people who actually know their stuff for a sanity check:

I’m planning to replace 2TB HDD with 2 1 TB MicroSDs. I know it’s not cost efficient and it may not be worth it but I really want to try it unless it’s super stupid even outside of the cost factor.

Two points of concern:

I heard MicroSDs biggest weakness is the limited writes before it breaks?

I heard MicroSDs cannot be without power for a long time.

Plan:

My plan is to write the backup once (one write), and never use them as working drives but still power them up every couple months.

When backing up, I currently delete all of my HDD and just copy everything over, but I heard there are programs that detect the changes and differences and just update those, I’m hoping those will not count as full rewrite and not do a big hit on MicroSD life.

If I do it like that, would MicroSDs be near similar reliability as other storage methods?

(And also, I feel little stupid for asking, but you can encrypt MicroSD in Disk Utility in Mac just like any other drives, right?)