I'm not convinced with the reliablity of SSDs
Its been 50/50 for me! Iv seen one main SSD fail and one main HDD fail (Although when SSDs fail, they totally fail, whereas when HDDs fail, its often slow and you have time to recover some of the data). That said I have seen a lot of HDDs fail after they were removed from computers and left sitting for years; but Iv also seen 1TB HDs from the bargin bin in Lidl last for over 10 years. I think like most mechanical things, if you treat a HD with respect, and power it up every few months, it can last a very long time
For my own storage I use
G-Drives, which as far as I know are enterprise Western Digital drives in fancy cases; they are mostly discontinued now, but you can still find them in some stores and on ebay. They are a bit overkill, but I just really enjoy them as objects; the cases are beautiful and its really easy to replace the HDs in them, so I'll prob have them for a long time!
I also run a program called
DriveDX - it gives you real time stats about the drives and their health! Im not sure how useful that really is, but stats are nerdy fun
(Apparently my main storage drive has been running for 22,200 hours and has been restarted 41 times and the coldest it ever got was 9c!)
For really long term large storage;
Amazon Glacier Storage is really good - its intended for long term archiving and it only costs a few cents for hundreds of GBs. You essentially upload files here and abandon them; they give you a unique request key and if you send them that key years later they will retrieve the files and send them back to you after a few days. No one really knows how it works, but its probably some sort of magnetic tape storage! (There are also non Amazon alternatives out there, but Iv not tried them!) - I have about 100GB of Nightcore I backed up in 2015 on there
As well as what I call doomsday backups I make every few months (for use in the event my house burned down or flooded).