>>106248752
>>Old thinkpads running Linux are insecure
They are in terms of firmware (unless you coreboot? idk), CPU microcode, and GPU firmware. That is true. Companies will stop providing updates for these things at some point. It affects even Linux/BSD distros because they still have to interface with this proprietary software.
Most of the issues you describe affect computers as well, even those running Linux. The mobo firmware is a huge chunk of proprietary shit, the CPU code is a huge chunk of proprietary shit, and if you have NVIDIA so is the GPU code. You can use corebooted ancient tech but then that won't have up to date drivers, as I specified in the above paragraph. There is no perfect solution.