It contradicts you calling them "middling". Bayern and Germany, middling teams
The years you mentioned the teams with higher highs and lower lows were at their lows. Just like now. Look at how the big teams are doing in their national leagues / competitions.
Bayern is steady as she goes without having the same heights (like the AC Milan teams, Juve teams, Real and Barca teams, Liverpool teams and even MU teams).
Bayern wins when everyone has an off "day" (year). The Pep Barca team (for example) won even with other teams at or near to their all time-heights with great great teams. Same for Liverpool (when they were at the top). Bayern does a perpetual Chelsea 2012++.
Whenever Bayern comes up against one of those "all time heights" teams they lose. In years where there are few great teams around Bayern get to or near the final and then lose.
Hence their large number of losses in finals (and semis). Just like the German national team which never reached the heights of the great Brazilian, Italian, Dutch and more recently the Spanish and French teams. German win when everyone else is having a bad world-cup but the German team itself is more consistent (covering all of the basics) rather than being GOAT level. Germany (national) has a dismal record against Italy (of all teams) because in addition to their skills and expression Italian teams are also very organised which negates the German consistency strength.
"While Germany has won more international championships,
Italy is largely dominant in the head-to-head international match-up, having beaten Germany 15 times in 35 games, with 12 draws and 8 defeats.
[6] Moreover,
Germany has never won against Italy in an official major tournament match, with all Germany's wins over Italy being in
friendly competitions—however, Germany had overcome Italy on penalties following a draw after extra time in the
quarter-finals of Euro 2016.
[7] A draw in the
group stage of Euro 1996 also eliminated Italy from the tournament, while Germany had already qualified for the knockout stage.
[8][9] There were also four matches played between
Italy and
East Germany which resulted 1 win for each country and 2 draws."
Germany–Italy football rivalry - Wikipedia
Nothing you said refutes this ^.