Their ambi mice are decent. I use a G300S at work, and I think they have some fancier mice that are also ambi while having features like wireless charging and the toggle for smooth/ratcheted scrolling.
The only company I know of that makes an actually left handed mouse is Razer. Decent hardware, but if you're on a Mac their drivers are even worse than Logitech's. There's nothing worse than having your mouse stop working because the internet is down.
Good point, for some it is like being forced to buy a two right shoes to fit upon your feet. Let alone the aspect of mouse size and the analogy gets down to shoes only available for right feet and then sizes 6 and 11 only.
With that in mind - how hard would it be to make a mouse which had a gel top that would mould to your hand. Could have a gel that is perhaps viscus when an electric current passed thru it and solid when not - allowing you to setup the mouse to fit your hand. As for buttons, well, that has been one of the easier ones to fix and about the only area you can customise a mouse (switch left and right mouse buttons) which is your standard OS configurable.
Razer made a left handed Deathadder in ~2011. They've since been discontinued, I have 3 of them and can't switch away. I've gone through probably 5 others. The tracking is nice and the feel is very good, but the scroll wheel is made from acrylic and tends to warp over time. The left, right, and middle buttons basically suck and wear down. The toothed shaft on the scroll wheel is also very tiny where it meets with the rotary encoder and is very prone to snapping off or wearing down due to friction.
All these problems and I fear I'll never see a better left-handed mouse.
I switch between my left and right hand every couple hours. The scroll wheel is great but no free scrolling. The buttons are amazing. I think I charge the mouse once every two weeks.
3D Connexion, the company that makes the 3D mouse (for CAD) also makes a regular mouse, and it is available left handed. I haven't seen one in person so not sure what the overall quality is like.
I'm always jealous by this type of mouse, while I'm stuck using my cheap sad ambidextrous Microsoft mouse.