Python is a widely used, high level, interpreted, general-purpose programming language with dynamic typing. It supports procedural, functional and even object-oriented programming. Interpreted languages have the benefit that code can be executed right after it's written, which speeds up the coding, testing/debugging cycle resulting in faster development.
Python is considered very easy to learn by anyone, even those new to any programming language, because it was designed from the beginning to be easy to read and write. Indeed, concepts, designs, and logic can be expressed in very few lines of code.
Given its interpreted nature, Python is much slower than C++ and .NET, but a bit faster than MAXScript.
Python allows for extension modules written in other programming language to interface with it, providing functionality in a wide range of domains, such as GUI programming, data science, database access, web programming, etc. Your own Python scripts can be packaged as extension modules, which you can distribute either as source code or compiled to byte-code. In addition, Python is available under a free license and it is multi-platform. Python learning resources are plentiful.
3ds Max integrates a Python 3 interpreter. The pymxs Python API (or Python extension module) allows for developing tools for 3ds Max. The PySide6 extension module included with 3ds Max allows these tools to have a rich user interface. The tools developed in Python for 3ds Max can take advantage of the rich universe of extension modules available for Python 3. Finally, those familiar with MAXScript will be able to extend their tools with Python-based functionality by importing Python modules into MAXScript, and calling into them. As of 3ds Max 2021, developing plug-ins in Python is not yet supported yet.
Several other Autodesk and non-Autodesk content creation tools support Python scripting, such as Autodesk Maya, Autodesk Motion Builder, Autodesk Fusion, Blender, Houdini, various Adobe tools, and more.
The qualities of the Python programming language, coupled with the multitude of ways 3ds Max is used by talented artists, alone or in combination with other content creation tools, makes it the logical choice for technical artists and pipeline developers, especially when there is a need for tools that work in more than one application.
Bottom line: if you don't consider yourself a professional software developer, value speed of development over the performance of your tool, your tool needs to interface with web, database, data-science, AI, etc. technologies and/or other digital content creation tools, choose Python as the scripting language in 3ds Max.
For more information, please see the 3ds Max Python Developer Guide.