Your last paragraph puts it well.

When one resorts to war for a solution, it needs to be a war. War is not civilized, elegant or pretty. Imposing rules and restrictions on one's behavior to try to make war more acceptable results in the nonsense we see here. The military solutions are not successful because not enough resources are available. Not enough resources are being committed. This is a token gesture. And we can't hurt civilians, and on and on. This isn't a war, and therefore the military forces being used are not winning it.

World War II, so widely admired here, was a total war. Everyone was committed to it to the end, and few restrictions were self-imposed. Need to invade some neutral country? Get going. Bomb civilian population centers? Certainly. Be ruthless. Be brutal. Do "what it takes" to get the required results. We'll celebrate peace at our victory. If NATO ever goes to war with Russia or China, it will be WWIII, and become that total (and probably nuclear.)

Nowadays, we want the military to go in "in limited fashion," and conduct "surgical strikes" that don't hurt "non-combatants." And we want to fight the flames shooting out the window, but not turn off the gas supply that's feeding the fire. We have some little fantasy notion (probably from watching too many war movies) about how wars should be. They should be "clean." They should be acceptable. And the good guys should win nobly. And our allies always need to do more (whether they are capable of it or not.)

Iran is supplying a regional network of allied groups which share its cause. Want it to stop?
Focus on Iran. Conveniently, Iran has attacked Israel. A war is already started. Give Israel both the military tools it needs, and the blind eye required, and Iran will no longer be doing this. The allies it supports will lose that support. They will weaken. They will either stop, or be easier to deal with through some sort of "token effort" as we're willing to undertake.

Don't look to the Saudis, or any of the other regional entities beyond Israel. They have even more self-imposed restraints tying them up than NATO does. The Saudi royal family governs at the pleasure of the Wahhabi clerics. Piss them off too badly, and they will turn the populace into a revolutionary mob. The Saudis will then have bigger internal issues to worry about. Wahhabis are not overly fond of Shia Houthis, which is why the Saudis can go in in the first place. But, it is distasteful to fight a totally unrestrained war against "brother Muslims." That sort of thing we reserve for Israelis. So, the clerics watch the royal family, and warn them when they reach any level that is felt to be too much.

Back during the Gulf War, a member of the Saudi royal family was conducting an interview with a member of a major US news network. He shook his head at the reporter, and told her the American people have absolutely no clue the tightrope the royal family has to walk every day. They are considered by the Wahhabis to be the guardians of Mecca and Medina. That is their primary duty, and they are allowed to govern "without (much) interference" as long as they do that. If the clerics deem them to be deviating from it, or doing anything detrimental to it, they raise hell. For the royal family to remain in power, they must pacify these people.

Egypt has similar concerns. Sure, this is hurting their revenue. But, they can't be seen as supporting Israelis over fellow Muslims. So, they are really pushing to try for a diplomatic solution, and will not consider any military options. I don't know anything about the UAE, but I would bet it is like this for the whole region. Houthis are Shia. (And why they are backed by Shia Iran.) Any regional entities engaging them militarily are a Sunni sect. But, it is then seen as a quarrel between brother Muslims, and limitations will always be applied.

Want this to stop, and want it done by military means? The West isn't into "Muslim brotherhood" if we go to war. And if we actually want to win that, we need to make a much, much deeper commitment. Israel and Iran are already now pretty much at war. Want a proxy? There you go.