The stability that Saudi Arabia desperately wants and needs to project has suffered many (some self-inflicted) wounds.
Trump publicly emasculated the King a few days, saying (rightly) that the Saudis wouldn't last two weeks without US support:
Trump says Saudi Arabia's King Salman 'would not last two weeks' without US support | The Independent
The Crown Prince seems petulant, vindictive and unpredictable. He has made a lot of enemies among the royal family and the religious. The floatation of part of Aramco, upon which his whimsical dreams of diversification depend, seems to be further away than ever.
The blockade of Qatar is increasingly ineffective, and evidences little more that a bullying approach (or had they hoped to steal Qatar's gas and wealth?).
The war in Yemen is a disaster - mainly because the Saudi (and Emirati) armies are disorganized and ill-disciplined - everything an army should not be. To misquote Lord Haw-Haw, the Saudi Army couldn't beat the tinkers out of Galway. If it were not for their air supremacy the Saudis would have been humiliated by now.
Meanwhile the Saudis fly a plane-load of goons to Turkey to kill dissident journalist Jamal Khashoggi:
Saudi journalist 'killed inside consulate' â€“ Turkish sources | World news | The Guardian
All of this against a backdrop that suggests that Saudi Arabia is the wellspring of much of the virulence that affects some parts of Islam, specifically Salafist-jihadism, and the terrorism that expresses this. Let us not forget that the role of Saudi Arabia in relation to the 9/11 attacks has never been published:
The 28 Pages - Wikipedia
We have all grown up assuming that Saudi Arabia is a monolithic unitary state, but it is no such thing, it is just the sum total of the lands that Ibn Saud managed to conquer. The kingdoms of Hejaz and Nedj could easily resurface, though perhaps more likely as Marxist republics, and the Shia-dominated Eastern provinces (where much of the oil is to be found) have never been subdued.