I guess it depends what you mean by "custom watch faces" but I've got 12[1] things that show different variations of clocks and widgets installed on my Watch and the Watch app offers a few more[2].

[1] Activity Digital, Solar Graph, Modular, Infograph, Modular Compact, Liquid Metal, Solar Dial, Unity Lights, Gradient, Pride Woven, World Time, Pride Threads.

[2] https://imgur.com/a/A9u4EYr

They do not and I've been wanting a 24h analog dial on mine with nothing else for years... Pole Clock's timezone hour hands would be a bonus though!

It shouldn't be surprising, that's very typical of Apple.