When you look at the make-up of your average adventuring party, you will usually find one or two characters you absolutely don't want to see in any kind of melee combat.

This is manageable when you're fighting in a confined space where melee fighters can block the way to the members of the squishy community but in a more open battlefield, grappling and the ability to move opponents where you want to (and in turn, stop them moving where they want to) is very useful indeed.

So there's your answer for grappling: its usefulness is situational. Sometimes it's a good trade-off to give up an attack for the chance of controlling your opponent, at other times it isn't.

My answer to the disarming part of the question is a single word: monk.

When you look at the make-up of your average adventuring party, you will usually find one or two characters you absolutely don't want to see in any kind of melee combat.

This is manageable when you're fighting in a confined space where melee fighters can block the way to the members of the squishy community but in a more open battlefield, grappling and the ability to move opponents where you want to (and in turn, stop them moving where they want to) is very useful indeed. Especially if that squishy character is concentrating on a spell.

So there's your answer for grappling: its usefulness is situational. Sometimes it's a good trade-off to give up an attack for the chance of controlling your opponent, at other times it isn't.

My answer to the disarming part of the question is a single word: monk.