2 trillion market cap? Corrupt russian oil and gas companies trade at 4x earnings. At that valuation with annual earnings of $90 billion aramco should be valued at more like $360 billion. Sorry, but that's the penalty you pay for being a corrupt journalist murdering autocrat.
The difference is that Saudi oil reserves basically cost nothing to extract. Maybe $5 a barrel. You literally poke a hole in the ground and oil bubbles out.
That makes Aramco significantly less risky than your typical oil company. Even if oil goes to $25 a barrel, the company will still be solvent, and even profitable. Mismanagement (like Pemex) is basically impossible under these conditions. It also means less capital reinvestment is necessary, so more dividends for the shareholders.
Less market risk, less operational risk, higher cash yield. All those things drive up the valuation multiple.