Regarding boards and electronics, what will cause failure and "wear them out" is heat. If the chips run hot, they will age and fail faster (assuming they're a quality board and chipset to begin with). Mechanical failures always outstrip electronics failures. devices with repairable/replaceable parts will last essentially indefinitely. I cannot vouch for the temp control/airflow/cooling on all the higher end boards, but I expect they are better thought out than say a $30 Pico.
Both are good to stockpile. It's always worth having a broad base for long term use. But easily serviced mods are, IMO, preferable if you're thinking long haul. So is simplicity, and mech mods serve a role as well on the opposite end of the spectrum.
Both are good to stockpile. It's always worth having a broad base for long term use. But easily serviced mods are, IMO, preferable if you're thinking long haul. So is simplicity, and mech mods serve a role as well on the opposite end of the spectrum.