I have a Pixel 7, stock Android 14. It is my only phone and I love the stock system. But I am trying to gradually ditch Google and its services, for reasons well-known in this community and Lemmy in general. How much would I gain/lose using a custom ROM with/without GApps?
Update: Switched to GrapheneOS, no regrets :)
One thing others haven’t mentioned is SafetyNet/Play Integrity and Widevine L1. You can spoof basic integrity but not hardware attestation (AFAIK), so any apps which check for it may not work (typically banking apps and some games). You’ll also lose your Widevine L1 certification, which means streaming apps will suffer - Netflix will go down to SD resolution, others services might do something similar (or even not work at all).
Naturally, without the Play Store you’ll also lose access to any premium apps or apps/addons you’ve unlocked with IAPs, unless the app offers an alternative activation method.
Finally, there are many apps which may not even work without Google Play Services. microG or GrapheneOS’ sandboxed play services could help, but YMMV - and you’d still be using Google’s services in the end, which kinda defeats the whole point. So I wouldn’t recommend microG/Sandboxed Play Services.
If you mainly stick to apps on F-Droid though, most of this shouldn’t be an issue. So maybe before switching, ask yourself, can you live without your favourite closed source app(s), and use a FOSS alternative(s) instead?