What about all the apps that need the "Google Play Services" libraries?

There's always MicroG and the MicroG-infused version of LineageOS:

https://microg.org/

https://lineage.microg.org/

jc! but isn't microg also requires us to enable some level of Google Play Services?

Well, MicroG is meant to be a drop-in replacement for closed-source Google libraries on your phone (i.e. Google Play Services / Google Services Framework) but obviously it will still have to connect to Google servers if needed (although you're able to control for what purposes). For instance, push notifications for apps often use Google's Firebase Cloud Messaging platform and MicroG allows the user to still receive those notifications in the absense of Google Play Services / Google Services Framework.

I suggest you have a closer look at the MicroG website where this is explained, too: https://microg.org/

Cool :) I am using openGApps but I think it does not have this flexibility I will switch over to microg :)

I personally use microG and disable all of the features that call home to Google, except for those anonymized by microG. Works flawlessly, except for some apps that don't work but are easily replaced.

So instead of trusting the hardware or OS maker you’re trusting a random third party?

It isn't a random third party, it's a specific third party with a better privacy record than the hardware or OS maker.

You can build LineageOS yourself if you want. The procedure is on their website. Then you can also read the code to make sure nothing funny is going on.