As a BBQ hobbyist, thermometers are an essential tool, both cooking temps and meat internal temps have to monitored. Also, it's a matter of safety with poultry.
I have multiple; an instant-read thermometer to stick in for immediate results, a Bluetooth probe thermometer which I can track temps on my phone if I'm within range, and a WiFi hookup with two probes; one to track the cooking temp inside the grill/smoker, and one in the meat that I'm cooking, which I can track from anywhere with internet access from the app on my phone.
Yes, you can usually know a steak's doneness by touch, but I prefer to know for sure, and I often do a reverse sear on a good steak, meaning I'll cook it slowly (around 250°), sometimes with a little smoke, to exactly 120° internal, then sear it hot, over direct flame or in a cast iron pan, to finish it.
Note the pink in this steak goes from top to bottom, not just in the center with gray around the border. This is the result of lower/slower cooking then reverse searing.