This question and answer about Pathfinder 2 generated a lot more upvotes than I expected.
I guess because it accidentally highlights a big difference between Pathfinder 1 and 2, namely in 2 you do not need any free hands to cast a spell.
Now I am wondering if I should change the question to something more generic, like "Do you need an empty hand to cast spells?"
Right now it is quite hard to find, being about a specific spell.
The title of your question - "How can I use a somatic component while holding a weapon in 2 hands?" - makes it clear that it's a general question. The specific spell is what prompted the question, since it both has a somatic component and acknowledges the possibility of using the weapon with two hands, but the body of the post continues by asking the more general questions "How can I use a somatic component while holding a weapon in 2 hands?" and "Is it possible with any spell?".
If someone has essentially the same question in the future, it can be closed as a duplicate of that one.
It's also worth noting that you shouldn't edit a question in such a way that it ends up invalidating existing answers. In this case, though, I don't think your proposed change of title from "How can I use a somatic component while holding a weapon in 2 hands?" to "Do you need an empty hand to cast spells?" meaningfully changes the topic you're asking about. Titles are just summaries of questions - so if you could edit the title without editing the body and still have it be clear what you're asking, you're probably not fundamentally changing the underlying question.
Thus, it probably wouldn't be out of line to edit your question in this way... But it's also not strictly necessary.
If you think the general question is valuable, ask the general question separately. It will (probably) get closed as a duplicate, which leaves a pointer to the existing answer (as you want), but lets the normal site mechanisms answer it.
