The plow probably isn't the best technology for the example because it is such a substantial improvement in farming capabilities, but something like weaving loom technology or grain milling technology might work better. Because while they reduce labor, it is perfectly feasible to live your entire life using simpler techniques. Hand mills and hand weaving take a lot of labor but aren't hard enough to make living in any particular enviroment too difficult to sustain well into old age. And I can imagine many people scoffing at that tech as unneccessary and dieing without ever feeling a need or desire to adopt it.