I used to use smartwatch timers a lot. I bought a couple magnet timers to throw onto my fridge instead. Best $3 purchase I've ever made. Just smash the buttons, hit it, and go about your day.
Most magnet timers also remember the last duration, so if you use the same timer a lot for the same task (tea, for example), it’s literally a single button press. The same operation on any kind of smart device contains a staggering number of steps, each of which requires cognition and attention.
Magnet timers are also super cheap, so you can get another one if you have two favorite durations. A simple solution meets a simple problem