What's good about it is that if you know what you're doing you can install only what you need and keep your system small and tidy. Also, since it's a rolling distro, updates become available really quick and sometimes some of the updates introduce optimizations (meaning more performance) or better power consumption. And finally of course Arch has also an amazing wiki, they have hands down the best Linux documentation along with Gentoo, and they even have a page about Thinkpads: https://wiki.archlinux.org/title/Laptop/Lenovo