It's a common, slightly frustrating pattern: the steel body of a bottle looks the same after two years while the lid is cracked, the seal is loose, or the thread doesn't grip as tightly as it used to. This isn't a manufacturing flaw specific to one brand, it's a predictable outcome of how these two parts are built and used differently.
Different materials, different lifespans
The body is solid steel, engineered mainly to resist denting and corrosion, both of which it's genuinely good at over years of use. The lid, by contrast, usually combines steel or plastic components with a rubber or silicone gasket, the seal that actually prevents leaks. Rubber and silicone degrade with repeated compression, temperature cycling, and exposure to whatever's inside the bottle, in a way solid steel simply doesn't.
Mechanical wear adds up faster on the lid
Every open and close cycle puts mechanical stress on the lid's threads, hinge, or seal, hundreds or thousands of times over a bottle's life. The body experiences comparatively little repeated mechanical stress; it mostly just sits there holding liquid. More moving parts under more repeated stress means the lid is statistically the more likely failure point, regardless of brand or price point.
What this means practically
A warranty or replacement policy that specifically covers lids, separate from the body, isn't a minor detail, it's an acknowledgment of where bottles actually fail first. If you're comparing two similarly priced bottles and only one offers a lid replacement policy, that's a meaningful difference in total cost of ownership over a few years, even if the sticker price is identical.
The short version
The lid wearing out first isn't a defect, it's the expected lifecycle of a part built from softer materials and subjected to constant mechanical use. Check for a lid-specific replacement or warranty policy before buying, since you're statistically more likely to need it than a body replacement.