No, I’ve never struggled with battery life. My iPhone Xʀ on iOS 12 gives me 16 hours of screen-on time on Wi-Fi and 12 on LTE. Double that and whilst it would be amazing, I don’t need it. The Xʀ is enough, always. Even heavy camera use hasn’t been enough to make me need a charger before the end of the day. I don’t need more battery life than this. The iPhone Xʀ is perfect.
I do wonder however whether the absolutely massive battery on the 13 Pro Max (which isn’t twice as good as the Xʀ, but isn’t far), will finally be the model to reach the end of its iOS support lifespan with good battery life. Apple claims 28 hours of video playback (16 on the Xʀ), so I’d get 28 hours of light use, and 21 hours of full LTE. Maybe? I’m not sure. Even if Apple halves that through iOS updates, this model might be the one to have enough battery life for a full day throughout its entire update lifespan. It isn’t twice as thick.