Any writer that says something similar to Google or Apple are "the world’s most highly valued company" should be ignored. If they are going to twist the truth on this what ever else they say is unreliable.
There is no publicly traded company that is even close to the value of some non-publicly traded companies, ie Saudi Aramco.
That is like saying that the US Federal Reserve is a more valuable non-publicly traded company. The writer is implying that there is no public market to value that business. While Saudi Arabia mulls over bringing ~20% of Saudi Aramco public, this is still a far cry from the business having a proper market valuation on par with the likes of Apple or Google.
There is no publicly traded company that is even close to the value of some non-publicly traded companies, ie Saudi Aramco.