[OptionOfT]

But it's kinda the same as a trial where you have to put in a credit card number.

If they auto-charge once the trial is over, I don't like them. That is a dark pattern.

Equally, with this, AWS could very well ask you, the user, what you'd like to do if you surpass the free tier. Charge? Or turn it all off.

On top of that they could instate default thresholds so that you, the person who just started their free trial, does not get bill shock when you forget to turn of that $200/h machine.

[paulddraper]

Almost all trials tell you how much they'll charge you.