Are macport dependencies for a port, potentially fulfilled by dependencies of past ports ?

As someone new to MacOS and new to macports, I am yet to fully grasp how macports works. I come from Linux world, where packages are binaries and their dependencies, s.a. shared libraries are also available in prebuilt form, that are pulled from centralized repositories based on what is is declared by package builder as requirement, some fulfilled by binaries and libraries that are already installed, and anything missing is pulled from the repository. For Macports, having already installed 5-6 ports that seem to pull the sourcecode for the main utility and all of it's necessary dependencies, I still see subsequent ports taking equally long time so wondering if they really have unique dependencies, or are common dependencies fulfilled by what is already installed on my system ? After you have installed quite a few ports, do the subsequent port installations get faster, because you need to pull (& build) less and less of additional dependencies ?