Last I checked (circa 2017), bioplastics like PLA had poor heat resistance. This made them unsuitable for certain applications like bushings or gasket seals. IIRC "heat resistant" varieties of PLA are rated up to 120 Celsius, which is good for many applications but not all e.g. automotive seals, washers, and bearings.
Footnote: I was going to compare the properties of heat-resistant PLA to those of PTFE aka Teflon, since the latter is commonly used in heat-resistant applications, but after some Googling I've learned PTFE is not petroleum-based.
Footnote: I was going to compare the properties of heat-resistant PLA to those of PTFE aka Teflon, since the latter is commonly used in heat-resistant applications, but after some Googling I've learned PTFE is not petroleum-based.