I highly recommend it. Piano is pretty challenging (and big), violin is even harder to learn when you're an adult. I bought a violin as an adult, but never really learned how to play it. You have to really dedicate yourself to it.

I also play clarinet and guitar. I hardly ever touch my clarinet now, but I love to sing with the guitar - it really helps me to relax when I am stressed.

Some instruments are a little easier than others. If you play one instrument already it is easier to learn to play another one. Knowing the theory help a lot. I started playing piano when I was a child, guitar and clarinet - when I was a teen, ukulele in my early 20s. Violin is still on the list, but I don't think I will ever really learn it. Mouth harmonica is pretty fun too

If you are seriously considering - give it a try. There is a wide selection of instruments for beginners on Amazon for really low prices (that's how I got the violin ). You can find all sorts of free tutorials online. I personally like YouTube tutorials because there you can see how to do something (e.g. how to hold a violin correctly).