In-house frameworks

In-house frameworks

Recently I graduated from university/college and immediately landed myself
a job. The company has versions of software it gives to it's clients,
however the software is largely, or rather entirely, built on an in-house
framework.
This in-house framework almost abstracts everything from the 'developer'
in terms of lean Java code and instead provides helper methods for almost
EVERYTHING. For example, creating a UI and interfacing with the back-end
is done entirely on top of their framework using their 'API' if you will.
My immediate thoughts are now - Do a year of experience and get out
otherwise I will be locked in and too afraid to leave in the future.
My questions are: Is this common practice in the industry? Will this
stagnate my skills? Should I bail?