For the thermostat it could well depend on the context to how much the latency matters.
If your recording average ambient temperature it probably doesn't matter much. If instead it is part of a physics experiment it could matter a lot. If it is part of some industrial control system [1] it could be critical.
For the ordering button the time taken doesn't matter, but the less time it takes (especially with the wifi hardware), is going to be a factor in how much power it consumes, and therefore battery life.
Comments
For the thermostat it could well depend on the context to how much the latency matters.
If your recording average ambient temperature it probably doesn't matter much. If instead it is part of a physics experiment it could matter a lot. If it is part of some industrial control system [1] it could be critical.
For the ordering button the time taken doesn't matter, but the less time it takes (especially with the wifi hardware), is going to be a factor in how much power it consumes, and therefore battery life.
[1] https://en.wikipedia.org/wiki/Control_theory