I will never even hint that a player is making a bad decision or a mistake or doing something unwise. After all, if I did, I would just be doing it 99% of the time. And that would not make for a fun game.
A good half of all player just play any character as themselves. And most of the rest that try a bit, don't put all that much effort into it. And they only remember to mention their character when they need to try and exploit something or try and backtrack something. Or try and cover their own mistakes, foolishness or just not paying attention.
Only a rare few play their character all the time.
A typical character from a typical fantasy world would know a ton that a typical player from 2024 would not know. Even more so the D&D era of like 1300 AD vs 2024. Plus you have city vs country. As a Country person myself, I have hundreds of skills city people don't have. And most of them are the same skills that a person in 1300 ish would have had: hunting, fishing, and general survival off the land. People from cities and suburbs often don't have such skills. So when role playing, if you know things for 'real' you can use it in the game.
And beyond this goes just common sense. Where a lot of typical characters would never, ever do or fall for anything the typical character does.
A character is often just played as a bit of a 'ideal' version of the player. So what does a super smart wizard character do on a night? Well, they go to a run down low life bar and want to get into a ;cool' bar fight...as this is what the player fantasies about doing. It's not exactly what a tyoical super smart wizard would do....but then it does take all kinds to make a world. So you can have smart wizard that love to drink and bar fight.....as it is cool to them.
So as the DM you can't tell the player "no your character is too smart to go to a bar and start a bar fight as he thinks it's so cool. It's not cool....it's dumb".
So like an hour of game play later, when the wizard character is arrested for mass murder....as he was 'so cool' he slaughtered folk in the cool bar fight....the player can't then say "wait, my character is too smart to be arrested for this." And that might be true....for the smart wizards that stayed home and read a book, no the wizard trowing a drink in an orcs face and saying "you want a piece of me bub!"