Is Procreate really worth it for casual drawing?

If you're only drawing as a hobby and don't have very specific needs, free apps do the job just fine and it's not worth spending money. That said, 12 euros is really not much, and Procreate is more intuitive and streamlined compared to the others: if at some point you feel the need for more sophisticated tools or you just want a cleaner experience, the price is absolutely not prohibitive. Try it out with what you have now, and if after a few weeks you notice you need something more, then make the jump.