In my honest opinion, the best instant pot for a single man, woman, or student is: Instant Pot Duo Mini 7-in-1 Electric Pressure Cooker
In my honest opinion, the best instant pot for a family of 4 is the Instant Pot 8QT Aura Pro. It has an easy to read display, a good variety of functions and will serve you well for a long time.
Before I get into the nitty-gritty, the best choice that gives you many options in terms of size and usage is 10 quarter big instant pot called Instant Pot Duo Nova Pressure Cooker 7 in 1
So quick and short answer is that the instant pots are worth it. They might not replace all your home cooking tech you have, but they will do their best. There is sauteing, steaming, searing, yogurt making, even baking, and many other techniques and options that can instant pots provide.
In general, you can say that yes, instant pots are safe. If you are following the instructions and you are not overconfident in your abilities and options. But, as always, anything can happen…
The instant pot works on a pressure basis. It can create significant pressure and temperature above 212°F (100°C) and force the heat into the food via the mentioned pressure to fast forward the cooking process.