I think people are talking about different things.
for my own Touring Sports: "Smart Entry" means i press the fob to unlock the car. Then, once sat in the car, I press the Start button. (the car senses that the fob is nearby).
by disabling Smart Entry in Settings, the car no longer senses my nearby fob. So i need to press the fob on the Start button (ie. make contact) to start the car.
This is no extra hassle for me.
With Relay crime, thieves send a signal to your Fob, which amplifies your Fob's unique signal for them to open the car door. (i keep my fob in an effective Faraday bag, which reduces this Relay crime possibility). But even if i didn't, and they were able to amplify my Fob's signal they cannot now start my car, because they need the actual Fob to be in contact with the Start button to start the car.
It's true, there's no foolproof way to stop crime, just to reduce risk. And Toyota luckily have given us this option to turn off Smart Entry.
I realise that for other cars, you can even open the car door without pressing your fob, just having it in your bag or pocket. This is terribly convenient, but in my own mind, unsafe.
I'm unsure if thieves can actually copy your Fob's signal as you're pressing the key. If so, then they can easily open the car when you've left.
But switching SmartEntry off, they will not be able to start the car without having the Fob.
On a separate note, there have been 3 break-ins in our street over the last 12months, where the only thing the thief took were the car keys, thus stealing just the car. So it's definitely worth NOT keeping them hanging in the entrance of the house!