Power supply defects too common

The number of related posts indicate that power unit failure is a common fault on Sonos products and that the only solution is to replace the component at a cost of 70% of the original price. I expect products that cost between $700 and $999 should last more than 3 years. In the last 2-3 years I have had this happen on a Play 3 and now a Sub. I see that others have fixed the problem themselves by changing a capacitor or reattaching loose wires, none of which would cost anywhere near the replacement fee, if an authorised repairer was available. Coincidentally I have not have any other problems, and for this reason have become suspicious that the frequency of power unit failures across these products could be an inbuilt defect designed to cause regular replacements to occur. Right or wrong I cannot justify the cost of repetitive expensive replacements for the sake of what may be the result of a loose wire or an inferior capacitor that could otherwise be fixed for less. Combined with the fact that I now also have to Trade up a Play 5, the maintenance of this already expensive system is getting out of hand.  As much as I have enjoyed being Sonos owner, I am sorry to say that if this problem continues to reoccur, and the option to repair remains unavailable, I will not be replacing anything and that will be the end of my Sonos.