When an exterior finish fails within a couple of years, the paint is rarely the cause. Three things account for most early failures, and all three are decisions made before the first coat.
The first is moisture in the substrate. Paint applied over wood that has not dried through will lift, because the moisture has to leave and the film is in its way. The second is temperature: most products state a minimum application and cure temperature, and coating outside it produces a film that never fully forms.
The third is preparation. Coating over failing paint transfers the failure to the new film. The old edge has to be scraped back to something sound and feathered so the transition does not show, which is slow, unglamorous work, and the first thing cut when a schedule slips.