It's incredibly naive to suggest that Saudi Arabia does not wish to become a regional leader or that it does not wish to expand its sphere of influence beyond its borders and become a dominant power in the Sunni Arab World, if not in the wider region.
All states/countries around the world have these kinds of geopolitical ambitions, including small countries such as Qatar, Israel, Belgium, Vatican City, etc. That's the nature of geopolitics. All countries have their very own spheres of influence, no matter how small or weak they may be or appear to be, and all countries around the world are invariably destined to pursue a policy of expanding their spheres of influence abroad (i.e. beyond their national/state borders) for the purpose of gaining geopolitical leverages on the regional stage and, possibly, global stage. Even the smallest of countries (e.g. Qatar, Israel, etc) wish to become, and could become, regional leaders.
So anyone who suggests that Saudi Arabia hasn't tried to lead the Sunni Arab World is either naive or being outright disingenuous.
As for the article in question, I would agree with its author that Saudi Arabia has so far failed to become a real regional leader.
----------------------------------------------------
If anyone around here is interested in understanding the geopolitical goals of Saudi Arabia, then continue reading.
First of all, we must look at Saudi Arabia's geography. From a geographic point of view, Saudi Arabia is a large country. In fact, it is one of the largest countries in the world. Having said that, Saudi Arabia is, arguably, extremely unfortunate. In fact, I would make the argument that the UAE, although a much smaller country, is geographically more fortunate than Saudi Arabia by virtue of the fact that it has direct access to the open sea in the form of the Indian Ocean. By contrast, Saudi Arabia does not have direct access to the open sea, and is actually surrounded by various choke points in the form of the Suez Canal, Strait or Hormuz, and Bab-el-Mandeb.
Saudi Arabia's export-driven economy depends heavily on the long-term security and stability of these choke points. For countries such as Oman and the UAE, which trade mostly through the Indian Ocean, a political crisis in the Mandeb Strait is not as detrimental to their national economies as it would be for a country like Saudi Arabia.
Therefore, Saudi Arabia has no other option but to expand its sphere of influence beyond its national borders and into countries such as Yemen and Egypt. From Saudi Arabia's point of view, these two aforementioned countries are incredibly important.
Saudi Arabia, therefore, sees Egypt and Yemen as its first line of defense against hostile regional rivals. Saudi Arabia must ensure that both Yemen and Egypt remain on good terms with Riyadh in order for the Saudi state to feel safe and secure.
The problem occurs when other countries in the region begin to challenge Saudi Arabia's sphere of influence in Egypt and Yemen.
For example, Turkey is interested in expanding its sphere of influence beyond its borders as well. For Turkey, Egypt is a very important country since it is viewed as a gateway into the Red Sea and, ultimately, Indian Ocean. Turkey cannot reach the Red Sea or Indian Ocean without passing through Egypt. This means that Turkey must develop very strong economic and defense ties with the Egyptians.
The more influential the Turks become in Egypt, the less safe/secure the Saudis would feel. Naturally, therefore, the geostrategic interests of Turkey and Saudi Arabia will inevitably collide in Egypt. Egypt will end up becoming a battleground between the Turkish and Saudi spheres of influence until one of the two countries gains the upper hand, or until Egypt becomes powerful and assertive enough to push back both Saudi Arabia and Turkey.
Another country that will naturally cause problems for Saudi Arabia is Iran. For the Iranians, Yemen is seen as a gateway into the heart of the Arabian Peninsula. A strong Iranian presence in Yemen would allow Tehran to undermine Saudi Arabia's sovereignty and territorial integrity. It would also be seen as a great opportunity for Iran to expand its influence into the Hejaz region.
This is exactly why Saudi Arabia feels that it must have a strong influence and political presence in countries such as Yemen and Egypt. This is also explains why Saudi Arabia was willing to go to war in Yemen. For the Saudis, losing Yemen to the Iranians and Egypt to the Turks is akin to signing your own death warrant.
