I know what AviSynth is and I've used it many times in the past for my small home video editing/encoding needs. It also makes sense to me because I'm a programmer by trade so scripting it is not hard for me.
However I also realize its limitations - if I had to make a full move by stitching together many pieces, adding effects and what not else - it would most likely be possible, but hugely tedious. This is where full-fledged video editing studios like Premiere/After Effects/DaVinci Resolve/etc shine.
But... it also seems to me that they kinda make poor old AviSynth obsolete, since they can do it all and more. Yet all of these tools seem to coexist peacefully, used by professionals worldwide, which makes me think that there are some use cases where AviSynth is better suited than the visual tools.
So what are they? I tried to ask Google, but all I got was one very winded Quora post which boiled down to "AviSynth has better plugins which are also free". Which... I dunno, doesn't convince me. Most of the time, the state of the art algorithms and tools in the industry are found in the costly tools. They simply have more resources and motivation to be the very best.
So, if you had sufficient finances to choose whichever tool you needed, when would you use AviSynth, and when would you use a GUI tool? What are the use cases for either of these tools?