In most cases where Mikrotik HW failed, it have always been due to damage from thunderstorm or similar disastrous event.
In remaining cases it was all due to bad capacitors on board that bulged and had to be replaced. This happens mostly on RB4xx series.
After replacing them the board continues to work and probably will for years to come if you use quality capacitors.
Other way how HW might die is due to too high flash writes, so just don't do certain stupid things with scripting and logging.
Too bad RB532 is not supported anymore, there are many available on used marked. At least latest LEDE still runs on it perfectly fine...