Sony owns both now, but Crunchyroll was purchased from AT&T in 2021. Sony purchased Funimation in 2017. So while it is perhaps not 100% accurate to say that Funimation itself did the purchasing of Crunchyroll, the company that owned Funimation did.
Edit: it is also worth mentioning that after the acquisition there was an immediate decrease in new content added to Funimation, and within a couple seasons there was virtually none, as customers were being pushed to the Crunchyroll app. Many, but not all, Funimation shows were also copied to Crunchyroll, but none the other way.
I believe that part of the catalog is still free with ads, but most recent stuff is not. They've changed their policies a few times, and I haven't kept up with the details.