I recently got a Pixel 8a since my Nova 5t died from water damage and I wanted to try GrapheneOS, I wanted a smallish phone with eSIM and it was one of the cheapest phones long term when comparing OS update support length. I still prefer the Nova ergonomics with the fingerprint sensor on the power button and the power button below the volume but aside from that:

The notch is not an issue at all, it appeared larger to me in pictures.

The camera focus has not died on a motorcycle without vibration damping and the phone itself has not died to rain. The plastic back is also nice since I don't have to worry about it cracking.

GrapheneOS has only been problematic with Revolut from which I migrated and Sparkasse's online banking application, although their 2FA app works fine so I can still do everything in browser. Migrating away from them ATM. Past that GrapheneOS has been a joy to use. Very powerful yet simple.

Battery life is kinda iffy and the slow charging is a bit annoying at times.

To me the 9a looks like more of the same essentially so I don't know if I'd spend 550 Eur on it but I'm pretty happy with my 8a for ~330. Though realistically most of my love for it is probably GrapheneOS.