I'm using FUTO keyboard and FUTO voice input. For English speakers, it's great - I heard not so much for other languages. The swipe keyboard feature.is apparently not great but I've never used swipe keyboards before so I don't care.
For text to speech, I'm using SherpaTTS, which made its way onto F-Droid this year. After downloading my preferred voice, I remove the network and sensors permissions. It works significantly better than RHVoice.
Dark mode and large font are part of AOSP and works fine.
For maps, you can still run Google maps with sandboxed play services. Alternative navigation apps are Organic Maps (open source) and magic earth (closed source but very good privacy policy). You're also able to use web based maps via your browser such as google maps, bing maps, and apple maps via duckduckgo search - though they won't do navigation. Some people who want to avoid installing google maps will use a web based map app to find things and then plug the location into their more privacy respecting navigation app.
You can also comparisonalize such as keeping Google maps (or othrr navigation app) and android auto installed on another user profile. That's what I do. The profile is almost empty except for apps necessary during driving and the profile doesn't run in the background when not in use. I only use it if I need android auto.
The only major things I feel like I lack compared to iOS is iMessage and Apple Pay. Though, I've mostly switched to Signal which is the better messenger anyway and end-to-end encrypted RCS messages between android and iPhone will soon be arriving, which will finally remove any need for iMessage in the future for me.
NFC payments technically work on GrapheneOS, but payments using Google Wallet/Pay don't. If another app existed, it could work. Some people on here have tried to get Huawei's Curve Pay to work, which I have no desire to put anywhere near my GrapheneOS phone. Ultimately, the security reasons to use NFC payments over just using tap-to-pay physical cards is minimal. If you're that concerned, get an RFID-blocking physical wallet. Other than that, there's just the convenience of being able to pay for things without my wallet, which I've honestly never needed to do...ever lol.