I get what you mean, it does feel like that sometimes, but after watching more I've realized that Luffy is primarily an Anti-Imperialist, so the Sraw Hats do restore some monarchies, but in the name of expeling a foreign power who took over the country, which I'm all for as an ML, our first fight should always be against imperialism, as I'd argue that even the Taliban government is better than 20 years of imperial war to remove them from power and let them restore it again

Which arc are you referring to? If it's Skypea yeah, it's the arc with worst politics IMO, but the others are mostly on point, for example Alabasta is a critique of Bourgeois Revolution (directed by Crocodile), even the name of his organization (Baroque Works) is a reference to this time in (european) history, who at the same time represents an external power meddling in internal politics and Wano is crearly against imperial industrial capitalism depleting a nation's resources, starving its people and supporting an illegitimate internal power (which took over with foreign help)

Few things to note:

• Piracy in imperial Japan was one of the ways to true freedom living under an oppressive regime
• In the Caribbean and many places, one of the few safe spaces for LGBTQIA+ groups was in piracy, if you are already persecuted by the governments for who you are, you have nothing else to lose (and this is a recurring theme) - Oda did make some mistakes about the Trans community, but at the same time, in later chapters this has been way better handled ans there are well written transmasc and transfem characters. Also there is a fruit called the Hormone-Hormone fruit, which can change a person's gender in one touch
• The main world pirate policing force, the Marines, belong to the World Government, which is quite literally the Anglo-(north-)American empire. Also who is still the biggest Marine military in the world right now?
• Luffy's dad rides a ship called the Wind Granma, the same name of the ship that took our comrades Fidel and Che back to Cuba, besides being the leader of the Revolutionary Army, his design being loosely based in Fidel, in recent chapters he confirmed he is a staunch Marxist-Leninist (IMO) as he recognizes (in a flashback, so when he was younger), that in order to oppose the Imperial core they do need a military force of similar might, or else liberation will never last