In subduction, one crustal plate descends beneath another, allowing the two plates to converge. Why has subduction halted in the mediterranean region?

The subduction in the Mediterranean region has halted because the African tectonic plate has reached the harder crustal part of the Eurasian tectonic plate. Because both of the plates have a same crustal density, there's no subduction anymore, but instead, there's a collision that will start to slowly lift the area around the collision line, and in time that will create a very high and very long mountain range, similar to the Himalayas in Asia.