Android Mobile OS Snooping By #Samsung, #Xiaomi, #Huawei and #Realme Handsets https://www.scss.tcd.ie/Doug.Leith/Android_privacy_report.pdf
"The privacy of mobile apps has been extensively studied, but much less attention has been paid to
*the privacy of the mobile OS itself.* ...
We find that ... these vendor-customized Android variants transmit substantial amounts of information to the OS developer and also to third-parties (#Google, #Microsoft, #LinkedIn, #Facebook etc) ... " 1/2
"#LineageOS sends similar volumes of data to Google as these proprietary Android variants, but we do not observe the LineageOS developers themselves collecting data nor pre-installed system apps other than those of Google.
Notably, /e/Os sends no information to Google or other third parties and sends essentially no information to the /e/OS developers." 2/2
P.S. How much private data is send back also depends a lot on the configuration.
Much of the comparison between /e/OS and LineageOS is a comparison between opengapps nano and MicroG.