"Convenience" isn't the only thing to consider. For my garage door opener, I like the "convenience" of the light coming on automatically. The same for the walkways around my house and in my shed.
However, I also have 3 sets of switched lights in the garage which are used - individually or in groups - depending on what I am doing.
For my bathroom, bedroom, hallways, etc., I only want the lights to come on when I want them to be on. Sometimes I want the bathroom light on full. Sometimes the nightlight casts enough light for me to do what I need to do. Dimmers provide a multitude of levels in between on and off.
Sometimes I just want a little light in the bedrooms, sometimes I want a lot. Dimmers conveniently provide that option.
Feel free to automate your lighting to your heart's content. For some of us the "convenience" you seem to be pushing doesn't fit our lifestyle. For the little bit of "work" it takes to turn a light on or adjust a dimmer, I get exactly what I want, when I want it.