This is a very broad question, and not really the kind that Stackoverflow can help with. Trying reading How to create a Minimal, Complete, and Verifiable example?.
But to attempt to answer your question I need to break it down.
1) I assume that you are using the script editor / IDE for developing / debugging GScript (aka JavaScript) code. And that is the simplest way to develop Google Apps Script (GAS) software. There is no alternative to this for python or any other language. However it is not obligatory to use the IDE to write software that uses the Google Apps Script APIs.
2) This link, for example, is the Google Apps Script API quickstart that demonstrates how to use the GAS APIs from python.
3) However, to look at the big picture... you can regard GAS as an example of Serverless Computing, where the Google App Engine, AWS Lambda, and others (see the link) provide a straightforward environment for developing and deploying software without having to worry about packaging, containers, etc.
Docker might offer some advantages over traditional server deployment, but I would not regard it as an equivalent of serverless, as there is still a container environment to implement and manage.
The Pros and Cons of each are highly subjective, depending upon the nature of the problem your software needs to solve, and your starting point - if your business is already heavily into Azure or AWS then that might be the way to go. But if you require access to Google APIs for Maps, etc. then that might be the way to go, otherwise it probably boils down the specific services on offer, and cost.
