/e/OS is android lol. Yes it's better than the version of android that ships with phones by default, but grapheneos is still way better than e/os (even though they're all android)
Iirc E/OS is based on Lineage, but takes a horrifying long time to patch in security updates on top of Lineage's already somewhat laggy patches. If you choose to use it make sure you're aware of that going in.
Also, like IIGxC said it's a android. Maybe slightly more private that most stock versions on most phones. But that's like saying [insert Linux distro] is better than Linux.
Ultimately the real solution to a lot of these problems is likely to be a Linux phone OS. It's something being actively worked on, but it's still only half baked and I wouldn't recommend anyone daily drive a Linux phone. Maybe in a few more years it will reach a state where it's actually usable.
One thing that would help a lot is if some company stepped up to provide a platform agnostic NFC payment solution that worked on both iOS and Android. As far as I'm aware if you want NFC payment you have exactly one choice depending on your OS, and both Apple and Google brick NFC if you root your device.
I would definitely try it, but all the phones I've been looking at recently don't have any support whatsoever for any of those types of custom OS's. No Lineage, no anything. All because they're not flagship models and are more budget friendly phones (and have what I'm looking for: headphone jack and SD slot).
I like /e/OS, but the app lounge bothers me a lot. There is no uninstall button and it is not possible to add Fdroid repos... So I have Fdroid installed in addition to it.
I do not see an added value as if I had the aurora store installed + Fdroid.
IMO, the best addition of e/OS compared to lineage is clearly the tracker /ad blocker app.
I love /e/OS, but it's not better. I've had a lot of issues ranging from GPS being inaccurate, MMS not working, and most annoyingly : the play store alternative works (app lounge) works 1% of the time..