Benjamin, according to N.B's own tests, there is a clear reason to avoid newer laptops besides price or availability, which is that they have more fan noise under normal load.
Just look at the T14s Gen 7 vs Gen 6 as an example it's a comparison of roughly 35 dB versus 25 dB.
In addition, Lenovo refuses to replace the garbage Mylar touchpads with glass ones even though doing so would not be expensive, so why upgrade if there is no improvement.
Heck, a Thinkpad T480 bought on an auction site would better suit most people.