I am currently learning about SegWit and trying to understand what it is used for. It is clear to me that it was primarily introduced to overcome txid malleability, but...
Looking at this question and the answer looks like Bitcoin, by updating the way that Bitcoin script works, disabled the txid malleability even without SegWit. So you can no longer add additional content to the script, keep it valid and have a different ID. So, txid malleability is not anymore possible, not just through using SegWit, but also by using legacy transactions (P2PKH) and the unlocking script field. In the first answer to the referenced question, Antoine Poinsot also talks about third-party malleability, but as he said, SegWit is not the solution for that, so it can't be the purpose of why SegWit is used today.
So if overcoming txid malleability, as the main reason why SegWit was introduced, is no longer the main advantage of SegWit (since it can also be overcome without SegWit), what is?
One advantage/purpose, I would say, could be that there is an indication of the version of the script being used, so that the script language can be extended very easily.
What are the other advantages/purposes of SegWit today (not just today, but in general)?