What is the use of capturing the Suez Canal as Axis?

[Tachya]

That said, I am not sure if the number of convoys goes up, if they have to travel around Africa, instead of through the Med.

I tried it and it does, but not as much as you might think.

As Germany, importing 8 rubber from the Dutch East Indies uses 10 convoys. Restricting access to the Mediterranean to force them to go around Africa, it increases to 11 convoys.

The UK has a whole spiderweb of global sea routes, not all of them through the Med. After letting a new UK game run for a few days, they're using 71 convoys to haul stuff around. Restricting access to the Med, increases it to 74.

Looking at that, a new question occurred to me. How much time do these ships actually spend at sea, and how much time in port, loading and unloading?

 

[Eh up me duck]

There's no point in holding Suez as either Axis or Allies. North Africa is a waste of time.