Modernists keep using this verse to defend their modernist agenda and they are right... "the gates of Hell shall not prevail."
From this, they believe they can run wild and do anything with the Church they want. However, their agenda will not prevail.
Since God does not change, the Bride of Christ does not change. This unchanging (prevailing) attribute of the Church is called Tradition.
Yet ironically, Modernists keep trying to cancel Tradition, but are unable to because "the Church will always prevail."
St. Paul didn't say to hold to tradition for the fun of it or as an option. Tradition means holding on to the Church that Christ founded, not the church that modernists want.