They usually are for sure. Genshin's is comically the worst (there's a 75% chance for a 5* to be one of the *two* featured ones, and the coin-flip guarantee resets between banners, and it used to be worse than that), and they're mostly just "bigger number" than "core functionality".

The only ones in Star Rail worth much interest in are the ones that offer other utility you can't get otherwise, like counter-master Yunli's increases her chance of being targeted, which otherwise you can only sort of get via another specific character, so kinda hampers your team options.