If the Strait of Magellan was discovered in 1520; why did sailors keep sailing around the horn, after?

My understanding is the the straights are very dangerous and difficult to navigate and that Magellan was actually lucky to have done it successfully.

The channel is narrow and rocky. It was deemed safer by many captains of wooden hulled sailing ships to navigate around the horn.

From the link:

All of these, however, are notorious for treacherous williwaw winds, which can strike a vessel with little or no warning;[15] given the narrowness of these routes, there is a significant risk of then being driven onto the rocks. The open waters of the Drake Passage, south of Cape Horn, provide by far the widest route, at about 800 kilometres (500 mi) wide; this passage offers ample sea room for maneuvering as winds change, and is the route used by most ships and sailboats, despite the possibility of extreme wave conditions.[4]

Conditions for sailing in the strait were often worse than those rounding Cape Horn. The strait is subject to extreme weather conditions, which are made worse by the fact that the strait is narrow and there is little room to maneuver and avoid turbulence.

Conditions south of Cape Horn were pretty bad for the same reasons--conflicting ocean currents from the Atlantic and Pacific oceans, and the entirely different currents surrounding Antarctica. However, there is a very wide expanse of water there, and hence, a much greater margin for error.

The Strait of Magellen is quite dangerous to navigate. Even now, ships go "around the Horn" more often than through the Strait.