Gooey is probably easier to set up, but PySimpleGUI looks like it's more flexible and powerful. Look at your own battle and choose your weapons accordingly :-)
I have a feeling that most python GUIs are lacking in some area and for full creative freedom someone would have to go for flask or fastapi, build the UI with modern js-frontend frameworks and connect that frontend with the actual application using websockets or regular HTTP-Requests.
Without it I couldn't have produced Captain's Log, for example : https://captainslog.scarygliders.net/captains-log-2/
The initial version, 5 or so years ago (maybe a bit more, I do not remember) was based on a python library (sorry, I forgot the name but it was the major one at the time). It worked fine for a bit but moving to a kiosk browser and vue.js completely changed the game.
The backend was Python, then got replaced by a bus (mqtt) updated via golang microservices (they were in python initially, but then I wanted to learn go)
I might use this the next time I need to build out a small personal project. I've taken a rather strong liking to Python recently. So much is built into the standard library compared to NodeJS. Very useful for quick projects/ AWS lambdas where installing dependencies is a pain.
Do you have a good guide on wrapping this in a binary ?
Wouldn't be able to use it in a corporate environment though, the licensing isn't great for that.
Edit: Found it!
Edit: I have found the answer in the docs 
Unfortunately as the app grew the main loop became really hard to follow and I've started to miss callbacks or some sort of oop wrapper around the whole thing. I also noticed that any other backend than TKinter was more like a 3rd class citizen rather than an alternative. Other than that it's probably the best GUI programming entrypoint in Python!
Some of their naming conventions though are odd IMO but otherwise I thought it was an easier way to process images than a webapp which is my usual working area. Now that I think of it though, a juniper notebook may have also been a solution but I wanted to dabble with writing a GUI.
It's also true that as you want fancier interactions, you have to be clever to get the framework to do what you want. It's very good --- best easy-to-use Python GUI I'd say --- but it won't handle every fancy GUI requirement. (That's why you have PyQt etc)
I used to use http://urwid.org/ but It needs a lot of code to do the stuffs.
I look for a library that is packaged in Debian (if something is in Debian, it is standard and has long life).