Well, apart from some shadowcursed needle blights and shambling mounds, shadows, wraiths, shadow mastiffs and shadowcursed fists and harpers...
Sure... If the average person wanting to simply travel to Baldur's Gate starts wandering around all the bushes and side areas and abandoned buildings...
It's like saying "How does anyone get through the Wilderness when there's Owlbears and Mud Mephits and Wood Elementals and Phase Spiders" when those things require you to go off the beaten track to encounter.
Quite literally, outside of the initial scripted encounter with the Harpers that get ambushed, the main route through the Shadowcursed Lands is devoid of all of those threats. Just like in the Wilderness the main route through is devoid of all threats besides the Hyena/Gnoll ambush (And of course, the Gobbers that are set up in the Abandoned Village) which is atypical for an average day.
