And you are welcome to do so. Turns out that Eve is not actually forcing anyone to buy the device if they don't want to. It doesn't interest me much.I do this with my eyes and a handful of grass 😛
On the other hand, I DO like the internal version of the device, the updated Eve Room, that gives you humidity and temperature. And yes, if you feel you would rather just listen to your body and not use a machine you are welcome to do so.
The rest of us, meanwhile, appreciate, among other things, the graphs that can be drawn allowing one to see if their trends of interest (was last year this time hotter than this year?), and the ability to trigger automations (switch on the humidifier if humidity gets below 45%).