I don't think that actually holds up. There are certainly some people that want "ironclad guarantees", but the reality of cost here is pretty close: you pay $5/mo max for the server. The things that can cost more are either overages on bandwidth/dns (and here, 1TB of bandwidth on the low end is included, eliminating a lot of the flux from EC2), or things you choose to initiate, like snapshots.
It feels like the larger thing they're trying to solve, that I expect actually stops the majority of people who don't choose AWS, is the complexity around setting up VPCs/SecurityGroups/Subnets/etc.
Most providers in the VPS space already charge overages for bandwidth, and most of them don't support suspending the account vs just billing you.