The default mode of Lightroom does not create sidecar files. There are none.
Even when sidecar files are present, Lightroom does not use them for anything, Lightroom uses the information in the catalog file (except when importing, in that case the develop settings in the sidecar files are written into Lightroom's database and then used to display the photo)
The purpose of sidecar files for other software is indeed to store develop settings, as there was no other place to put this information; however this is not the purpose of sidecar files in Lightroom. When present, the sidecar files are simply a way to store your develop settings outside of Lightroom and allows Lightroom adjustments to be communicated to other software that can read Lightroom develop settings.