Your experience is either imaginary or ridiculously atypical. Its literally not a real thing. Devices with replaceable batteries don't normally fall apart unless you are in the habit of dropping them all the time. This isn't a design consideration or a justification.

Phones are designed without user replaceable batteries because it makes it slightly cheaper to manufacture, generates revenue from users who require replacement, and makes it less desirable to keep an existing device vs buying a new one.