CG/Visual Effects industry is still firmly using Python 2. Only in 2020 are they taking the first step to transition to Py3 [1]. Users and studios are held back because the Python runtime is used inside major applications; Nuke, Houdini, Maya as well as libraries and APIs. None of them have released a version that runs Python 3 yet.
The reasons for delaying it (mentioned in a footnote on that page) makes sense to me. Previous years were focusing on coordinating updates to GCC, Boost, C++14, Qt, and waiting on Python bindings for Qt.
Also, I've worked at a couple studios many people have probably heard of and none of them have unit tests covering much of their code. The focus is on tools that facilitate in-house artists where responsiveness to needs are valued over architecture and completeness. Requirements change for each project and previous requirements are often sacrificed (until a new project needs them in a few years).
I'm itching to move to Python3, but even for standalone tools I've felt it better to choose a completely different language (or Python2) instead trying to mix Python2 and 3 because having them co-exist creates more headaches in managing the environments, dependencies, and coding styles.
I am not sure how you could possibly know this. You have no idea what else they were working on instead.
If you haven't put in the priority to update your Py2 to Py3 apps by now, I really think your shop has the wrong priorities.
It's not just about Py2/3. Dependency rot is one of the worst form of technical debt. It often shows broken CI, broken security scanning, lots of generally broken processes that will just keep hurting a team further and further down the line.