Yeah, 4 months is too quick for a SSD to die and will definitely be covered by the manufacturer.
Cheaper SSDs use cheaper flash modules that wear out faster (I've heard some are only rated for 2000-3000 read/write cycles, and use over-provisioning to compensate). Average lifespan for those is 1-2 years. Premium SSDs use better components and, now that firmware revisions have fixed the problems with SandForce controllers, should last 3-5 years (still a far cry from the 5-8 year average lifespan of a HDD, with some lasting over 15 years). Some extremely expensive SSDs are rated for 1-5 million read/write cycles, but most are rated 50k-100k cycles.
Reliability isn't the best in SSDs, but it is improving. Personally, I have a backup runtime set up that regularly dumps an image of my boot SSD to one of my HDDs so I don't lose anything older than a day (2 SSD, 4 HDD setup). My Steam SSD is unprotected because it's just games and the saves are stored on my boot SSD and the game files can always be re-downloaded.