Plainly, microspikes are best thought of as the “on-trail” version of crampons, which are mountaineering-specific traction devices meant to be used on the permanent snowfields and glaciers of alpine climbing routes. Utilizing one for the other is often a recipe for an uncomfortable time out in the hills, though there is crossover terrain that some may opt for a lighter version of traction to shave weight on their back.
For one, microspikes utilize an easy to adjust elastomer harness system that makes them amenable to pretty much any type of footwear, while crampons are available in both full-strap, semi-automatic, and fully-automatic harness versions. All of these require the sturdy shank of a mountaineering boot to work properly.
In addition, microspikes are, well, micro, with much shorter traction points compared to their alpine brethren. The longest microspike points are typically less than 1/2″, while crampon points can reach an 1 1/2″ or more.