SSD lifespans aren't measured in years. You can have one living for decades and still function fine, due to the lack of any moving parts in the technology. SSD's degrade due to constant writing and rewriting data to its storage cells. In other words, the more you use it, the more it dies. Manufacturers usually list out the minimum terabytes of writes (TBW) that their SSD's are rated to be able to handle. It's usually in the ballpark of 300 to 600 TBW. Note that this is just the rated minimum, so your SSD is supposed to last longer than the minimum TBW.

You should check out CrystalDiskInfo. It'll tell you how many TBW are currently on the SSD. As for how long the SSD lasts, you'll need to check for the manufacturer's specifications for your particular model of SSD. If you can't find the manufacturer's specifications, knowing the current amount of writes will at least still give you a general ballpark of its remaining lifespan (ie, 20 TBW = still pretty new, no worries here; 500 TBW = I wouldn't rely on this SSD to live very long)

In general, though, 5 years of normal usage isn't very long. I think there's probably still plenty of life in that SSD, unless you spent those 5 years constantly downloading movies or something

If it ain't broke…

You have regular backups already. Unless you want to add fault tolerance with something like RAID, I don't see why you need to buy anything right now.

I'd say keep using your SSD and add frequent backups to your weekly or even daily schedule.

Maybe to minimize your downtime you could get a new drive but set it up in RAID1 with your current SSD.

Run hdparm on it and note the percentage used. If it's near 100% it may degrade soon (though drives can hit 120% and still function).