Bushings also tend to be made from softer materials (needed for conformance under load) which have better fatigue resistance but can't handle as much total load (lower yield strength). The failure mode tends to be over a longer time-span though, and can be detected by change in lash.
Bearings are hardened steel which can take higher total loading, but will often fatigue fail with micro cracking and spalling happening in quick succession, leading to catastrophic failure with seemingly no warning and lots more small parts coming free during the rapid disassembly.
Everything is a trade-off..
