Logitech MX Master 3S for Mac
The MagSpeed scroll wheel is the feature I didn't know I needed until I used it.
The MX Master is the mouse I've used longest without wanting to change. The shape is right — fills the palm, thumb sits naturally on the side wheel, everything reachable without shifting grip. It's ergonomics that took actual thought.
The MagSpeed electromagnetic scroll wheel is genuinely different to anything else. Spin it fast and it freewheels through thousands of pixels in a second. Slow down and it clicks precisely into ratchet mode. The transition is automatic based on scroll speed. Scrolling through long design files or codebases with this is the most efficient I've been with a mouse.
The Bluetooth multi-device pairing is what keeps me from looking at alternatives. Paired to the MacBook and an iPad, I switch with a button on the underside. The connection switches instantly — not the half-second lag you get with cheaper multi-device mice.
Battery life is measured in weeks. I charge it maybe once a month. USB-C means it uses the same cable as everything else on the desk.