Ehhhh...it works okay but the same fundamental serialization problem exists. The fact that dict can be roughly equivalent to JSON helps, but as soon as you start including more complex types you're going to have to use something to handle serialization/deserialization. Which really isn't that complex with Java if you're using a few convenience libraries: gson, orika/mapstruct, lombok all make it a lot less painful to write this kind of boilerplate serialization code.
The most common issue I run into is with datetime objects, but there are well documented workarounds. For more complex objects such as ORM objects, I think a lot of people use Marshmallow. That being said, I don't have a lot of experience, so I could be missing something obvious. What issues have you had with Python JSON serialization?
I wouldn't say I've had issues, I just don't think it's really been easier/quicker in Python than most other languages I've used except for the simplest use cases (when Flask jsonify does everything you need because your data is all just strings, numbers, and booleans already)
