I would prefer to use Graphene OS. However they only use Google products. I am not willing to suck Googles dick to have maximum privacy and security.

Lineage OS is better than any garden variety android operating system that comes stock with manufacturer devices. I can mitigate some of the privacy and security concerns that you brought up with 3rd party foss apps and manual intervention.

This is my happy middle ground. For I am not willing to compromise my morals and ethics by contributing to an evil corporation's profitability. Either directly, or indirectly. Very much for the same reason I wont use GitHub, Apple, or other Microsoft products too.

My plans for the next device involve a pinephone to have a full Linux mobile experience, but for now I am truly satisfied with Lineage OS. Been with them since the beginning. I see no reason to stop using their operating system any time soon. They have not abused my trust in any way. So far the community support has been great too.

Hopefully other manufacturers make more secure devices so Graphene OS supports them. However, like many things in life you can't always get what you want, but sometimes you just might find you get what you need.