Does an Instant Pot actually save time?
It is going to depend greatly on what you cook and where you are. Long braises can be shortened by hours. It is nearly impossible to cook beans in Bogota Colombia without a pressure cooker. cite

Lentils on the other hand. The recommended times in the IP manual and on the bag for not in a pressure cooking are the same. And as you say, with the IP natural release is not included in the time given.

Another time savings is not having to manage the cooking in the middle. Thanksgiving evening dumped turkey carcass, mirepoix and water. Set for 2 hours of high pressure. Ignore for three hours. Cool and refrigerate one gallon of turkey stock. No checking to see if it is simmering, adjusting the heat up, checking again, adjusting the heat down.