Look the passage of time that occurs in games like Baldur's Gate 2 is considerably different from Baldur's Gate 3. In Baldur's Gate 2 you are forced to do side quests to earn money to pay the Thieves Guild in order that they might get you in to spell hold. That is considerably different from having a mind flayer tadpole in your head that is going to cause your flesh to tear off your body and your face to split open. It is also considerably different because you are told immediately upon entering The Druids Grove that the Goblins now could attack the Grove at any time. You are also told that The Druids are performing a ritual and will be completing it at any time now. So there is a much greater story element related to time in Baldur's Gate 3. You are literally told that you have a limited amount of time but then the game does not actually limit you on your time or provide any consequences for taking too long. So the Developers set the stage implying that this is a time-sensitive game but then they don't actually make it a time-sensitive game.
That is the first part of BG2. Once Irenicus steals your soul, it's implied you will lose yourself to the Bhaalspawn essence / slayer (and the slayer transformation actually kills your character if sustained for too long, in BG3 you don't even get harmed for using the tadpole powers). But in practice you can explore the countryside after Spellhold, while Irenicus is chilling with your soul in the elven city, because -despite all the forces he brought there - he will never suceed at his plans. Your character always arrives on time to stop him, even if it takes them a year.
