Indeed, they sell phones with their OS preinstalled, but they also offer an open source OS for free for anyone to download an install. In the end they need some income, and I’d rather they sell phones (saving the user the trouble of installing another OS on their phones) than do it through ads or other ways that offer no value for a user.

CalyxOS is great, I hope it comes back strong. If you want to try another degoogled OS based on Lineage with flexibility to install/uninstall any system app (like microG) and a built-in tracker and ad blocker I’d recommend IodéOS: https://iode.tech/