Definitely not always. It depends on many different factors: your position, the size of your and your opponents' stacks, the type of game your opponents are playing (lose or tight). There are many different situations in which it is recommended to play AI with AK: you are on a short stack, in late position with no previous raises, you get a good flop (A or K). It is not recommended when you are in late position and there are many bets/raises ahead of you or the board is wet without an A or K. Or just opponent has low vpip and plays aggresive and you have nothing. In that case, it is better to fold for me.