I love rails, but despite its presense for over a decade, it doesn't feel mature. Something as basic as a native left join in ActiveRecord wasn't added until Rails 5.0, on June 30, 2016. Something as basic as native multiple database support wasn't released until Rails 6.0, on August 16, 2019, 15 years after its initial release... These are just two examples.
Regardless, it was fully supported in gems for years before it went into Rails. It's nice to have it in core. But to say that Rails doesn't feel mature without it?
Come on.