MicroG is an alternative to the Google Play Services found on nearly every Android device. It allows you to circumvent the need for Google’s proprietary software on your device while retaining nearly full functionality through open source software.
Previously, it was somewhat complicated to set up microG as it required ROM support in the form of signature spoofing and a lot of other preparations on the users end. A Magisk module was released to help ease the process, but it still required ROM-side support and some preparation, which stock LineageOS did not accommodate.
Now, XDA Member Simon94 has streamlined the process for a wide range of devices by creating an unofficial fork which has built-in MicroG along with F-Droid, the Play Store alternative for FOSS applications.
The benefits of microG include being able to enable or disable the Google services according to your needs and preferences. For example, you can disable SafetyNet or GSM and leave device registration enabled if you wish. Location services are also replaced with two open source alternatives (one by Mozilla and one by Nominatim) with the option to install others. What’s more, you will also receive OTA updates!
If you want to switch from LineageOS, it is recommended to clean flash microG LineageOS as the keys differ and it won’t flash over other LineageOS builds like an OTA update. You can change the keys but for stability reasons, it is highly recommended to just clean flash. Once installed, you will have to grant a few device permissions within the microG application, so open it and check the “Self-Check” section. You can enable everything or see what else you need to do from there. Keep in mind that nothing is guaranteed to work and could break at any time, due to the unofficial nature of the software you are using.
Check out microG Supported LineageOS!
Thanks to XDA Senior Member kurtn for the tip!