T14 gen1/2 or T14 gen 3?

Let's say each of them is a good deal in price. T14 gen 3 is $100-120 more than gen 1/2.

With T14gen 3 CPU (intel core i5/7 12th gen) having a monumental leap over previous gens, which is around double the performance, would you say it's enough a reason to go for this instead of T14 gen 1 or 2? Reason is I'm thinking of a reason to convince my relative to go for the gen 3. My thoughts is that it would last way longer than gen 1/2 (judging solely based on CPU power difference, assuming RAM is 16gb by default) in terms of being susceptible to obsolescence in the future. Assume their budget is only around gen 1/2 territory, but not too strictly there.

I need some critique in my reasoning. Suggestions are welcome.