In the current age of AI, open source means exploits can discovered directly through the code. The flip side is the patches can also be managed.
We are in that period between when software was good enough and when software is certified as secure by the writers.
The days of importing frameworks and libraries written by strangers is over. I would say the entire industry is not prepared at this moment for the unpatchable event where the only solution is to power off or disconnect.
Don't expect closed source to protect you. LLMs are very happy to analyse binaries and decompile functions you need. It's barely harder to deal with software you don't have the source for. I did both security and reveng work with LLMs and they don't slow down.