POP's default interface is fairly customizable. it's essentially GNOME with a few extra enhancements, including the option of window tiling and a custom app launcher, so it's extendable via GNOME's quite mature extension system and customizable through GTK themes, cursor themes, etc.

the thing about all linux distro is that if you hate the default desktop, you can just replace it with a different one. for example, im running pop on my laptop, and ive completely replaced GNOME with leftwm. you can make any distro act like any other, so as long as you're not starting with gentoo or something like that, you shouldn't really worry about picking the best one, especially when you haven't experienced linux yet and don't yet know what you find important in a distribution. personally, my only gripe with pop os is that i need the most up to date versions of packages for my workflow, and the pop os repositories are often out of date. that doesn't necessarily mean that pop os is bad, mind you, it just means that for my use cases, i should get off my lazy ass and install arch lmao