I'm confused because over the past 20 years I've owned four Stanleys[1] and used many more and never had those problems. Are you using the absolute cheapest ones they make? Because even the ones you get at Home Depot these days have metal innards that hold up over time.

One of mine got left outside in the garden for an entire winter. One side of the enclosure is sun bleached and I had to replace the blade, but otherwise it still gets used every week and works fine.

[1] This one. None of them have ever failed, I just keep 3 of them in different locations and physically lost (maybe loaned out) one a few years ago. https://www.stanleytools.com/product/10-179/hi-visibility-re...