Would a Raspberry Pi with linux be more secure?

Changing architecture won’t resolve anything, beyond having less compatibility in terms of both hardware and software on the Pi. A stronger long term option would be having an x86 machine that allows some level of expansion in terms of performance, disks, etc.

At least, this is what I’ve discovered. I still use my Pi devices, but I do not recommend them over a used thin client or some other machine.

Just know it will not be more secure.