As a Rails dev it's extremely rare for me to need some functionality that Ruby doesn't cover. If you're doing standard web development most likely you're gonna be fine with Ruby. I've been doing this with Ruby for around 8 years so I bumped into quite a few use cases...there are gems for all the standard things.
But yes outside web - data science, web crawlers etc...Python has the clear advantage.
But yes outside web - data science, web crawlers etc...Python has the clear advantage.