Is it easier to fly into Munich and hit the Romantic Road or fly into Frankfurt and hit the Romantic Road. My plan is to travel the Romantic Road and end in Garmisch then travel through parts of Switzerland and then hit Tuscany in Italy. Any advice? Frankfurt or Munich. We have 23 days of travel. Thanks!

It's six of one and half-a-dozen of the other, really. Flying into Frankfurt will save you from doubling back.

I would fly into FRA and make a big loop if that's an option.
Really nice rental cars (with small, fuel efficient turbo diesel or supercharged motors) are relative bargains and great in the Alps - esp with 5/6 sp man trans.
In 23 days, you can see a lot: the Rhinetal/esp the W side - Boppard N and the Moseltal - Trier to Koblenz - Castle Burg Eltz is my fav in Europa.
One night in Heidelburg - I like Gasthaus Backmulde, and a quick trip to the Routes des Vins in Alsace (overnight in Riquewihr). The Alps are not far into Switzerland and the Mt passes into Italia are amazing.
Returning through The Bavarian Alps is an easy drive, but you might miss Munchen, Salzburg, Berchtesgaden, etc. RT via RR through Rothenburg and Wurzburg.
Many more specifics on prior post here.
M

I think it may depend upon what airline you maybe flying. Since you have 23 days it will not matter and you may want to see more of Germany along the way. However, if I understand my geography, and having been to Germany many times, Munich is much more convenient for hitting the Romantic Road on the way to Garmisch.

Wurzburg, at the top of the Romantic Road, is about 90 minutes from Frankfurt. It's another hour to Rothenburg ob der Tauber. Garmisch is at the bottom of the RR so it makes sense to me to start in Frankfurt.