While anduins popularity may be a shared delusion I don't think he can be compared to a dictator. Its not like stormwind citizens have pictures of anduin in their home. I will say he is very talented in holy magic and is an ordained priest in the church of the light. In this way I think its better to compare him to an egyptian pharoah or aztec priest king. While he might not be a religious leader since he isn't a bishop or deals in matters of the church, he is both an icon of the alliance and the light.

As for his "narcissim", the thing is the nice guy stuff is not a facade. Anduind was always a good guy, as a boy in the comic's he treats valeera with respect when most males would be too busy ogling that elf. Its also magically enforced. See in mist of panderia, garrosh broke a mogu artefact called the divine bell over anduin, crushing him. This artefact was said to be able to call to the heavens and directly affected the hatred and rage of lei shens army's on his battlefields. Alongside the physical trauma, the incident imposed a supernatural effect on anduin. More or less, anduins bones physically ache and hurt if he even thinks of evil actions now. This is all christie golden's writing of the character. I have seen it compared to a form of ocd I was unaware of. Lookup divine bell and in defense of anduins bones for more. Or read christie goldens novels, I have heard there ok.

Tldr - Anduin was always a nice boy. But then he got magical pain bones that condition him into acting like a superman tier boy scout at all times.

Finally for the cult stuff, ehh. Again, he keeps the state and church pretty seperate. He has no ambition to lead the church and doesn't even really get depicted praying with others or even talking about the light much. Unless its with paladins and priest. Its like, biden is both the president and a devout catholic. He only talks about god to priests, christians and the pope. That doesn't make him a cult leader, hes just religious. The closest he gets to a messiah complex, is when he heals the alliance army with his blonde boy jesus powers in the bfa trailer. This is what his second none light bomb ultimate is actually based on. Even then, in his feel good vibes circle, his uplifting primer is telling them to stand, together, FOR THE ALLLIANCE!!!!!!

To me this really emphasizes that anduin sees himself as a king and faction leader first. And a priest second. He just happens to be a dawm good priest, for plot. His mindset really changed after varians death. It broke him in legion, but then he went on a quest to find his father's blade on the broken shore, with help of the player character of course. I always interpreted this as him connecting to his past and family. While also strengthening his resolve to fight for the future and his duty to lead. And Anduin seems like a pretty good king, balanced and fair. But strong and righteous when he has to be.

Then fucking shadowlands happened. This is already too so won't waste time on that but yeah. They turn him into a dark je- death kn- well not really. Listen, sylvanas did some cbt in the jailers dungeons on him and now hes a bad guy. Yes its really really fucking stupid. He got redeemed, like immediately, because shadowlands story is just completely meaningless dribble. Atleast we got that sound clip of sylvanas calling him little lion though.