Comment by m1333

Phone from 2009 uses SLC, or MLC with large SLC cache, thus capable of at least 10k FDW (full disk writes).

Modern phones typically use TLC or QLC within a inch of their physical limits (signal to noise ratio), thus qualified typically only up to 500 FDW, which translates into several years of use.

There are other mechanisms at play which further degrade this number, such as WAF (write amplification) and others