Really? Just influence?

Yes, just influence.

Sure, it dramatically changed consumer preferences in automobiles by raising the cost of gas. But that's very different from having geopolitical power. The OPEC Embargo failed completely to achieve its primary aim, which was to disrupt the U.S.' support of Israel. OPEC didn't intend to spur a shift in the fuel economy of automobiles. Probably quite the contrary. All of those changes you describe had no benefit to OPEC, and indeed hurt them somewhat going forward. OPEC thought they had a powerful weapon, but in the end it had very limited utility to them. The cartel gave them a lot of economic benefits, of course, and that wealth brought them a lot of advantages. But the ability to stop production didn't give them all that much sway in geopolitics. At most they were able to influence the foreign policy decisions of other countries, but they never had any actual control over those choices.

So while China's market dominance in certain products gives them a powerful tool to influence the choices made by other countries (like encouraging us to reverse our reckless tariff policies), it doesn't give them all that much power to use to achieve their goals. Some, to be sure - especially over those countries that are also within its military sphere of influence. But it's limited.