Earlier quoted context omitted.
Low cost, simplicity and customer service. AWS does offer Lightsail which is similar pricing.
The terms of use of Lightsail say you can't use it in a way that's intended to reduce your costs over EC2. So they have more free bandwidth, but you're not allowed to intentionally send your traffic through Lightsail to avoid the extortion of EC2 bandwidth pricing. They have cheaper CPU, but you're not allowed to use 100% of your CPU.
You cannot use Lightsail to work around EC2 costs, but you can use Lightsail instead of using EC2.