Using arduino with ROS: Using ros library vs serial communication in external script

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To use arduino with ROS, people majorly use the ros library by including it in their Arduino script. There is good documentation for it. But the drawback is that it takes more program and dynamic memory. You might have to shift things from Uno to Mega after incorporating ros library in your code.

Instead, if you use serial communication and use serial communication on Arduino's port using python/C++ script and create a ROS node there, then you can keep the Arduino script lightweight and still use ROS. Are there any drawbacks to this setup?