If the definition is so broad, my oven and fridge are computers.
Your oven and fridge (probably) has a computer within them, but they're not computers themselves.
According to that definition, yes.
You have programs, you have a UI to control them, they have a CPU and memory.
And "that definition" is the official dictionary definition and it works. There is no need to redefine it like you tried to.
Why not? They have buttons and speakers (I/O), I can program a timer on them, and there’s a little processor in there somewhere. How is that different from an iPad?
You're just making up your own definition of "computer" and then claiming a smartphone isn't one because it doesn't match your made up definition.