In Germany all SIDs contain "Immediately after departure contact ..." instructions (with the exception of two airports where it says "after passing 2000 feet contact.." (due to VFR traffic constraints) and Munich ("Remain on TWR freq until advised") due to simultaneous parallel traffic. This also works for different sector freqs depending on actual SID.
This procedure is in effect since twenty years or so and extremely efficient. I reckon the number of those who don't comply to be not measurable.