PLA is the default 3D printing material for good reason. It prints at lower temperatures than most alternatives, barely warps, does not need an enclosure, and holds fine detail cleanly, which makes it the most forgiving way to get a good print.

It is made from plant starch rather than petroleum, so it is biodegradable under the right industrial conditions and produces very little odour while printing.

Its limitation is heat. PLA softens at relatively low temperatures, so it is not the material for a part that will sit in a hot car or near an engine. For those, PETG is the better choice.