VFA relegated to 2nd tier status by virtue of the majority of strong clubs moving their season to season premier competition under the title of VFL in 1897.
SANFL essentially relegated to 2nd tier status when they entered their own team as a team in this premier league in 1991.
WAFL spiritually relegated to 2nd tier status in 1987 when they entered their own team of West Coast Eagles in this premier league and lots of fans would not stay around to watch the next tier down play after it at the same ground.
VFA killed off gradually during late 1980s and early 1990's to be merged into the 2nd tier state league we have now in Victoria but it is no longer VFA. Got gobbled up by the premier league and identity of long time VFA clubs mostly gone.
That is of course because of the AFL, none of those leagues apart from the VFA were officially rated as 2nd tier before the VFL expansion and renaming it the AFL.