I think what amirathi is saying is why would someone use your SaaS vs using AWS. Using AWS on it's own is painful so I get your value prop but there are also some solution in this space already such as Serverless[1] or Apex[2] that make this process very easy. I don't think it's necessarily a bad idea and the fact that there are products out there shows there is a business for it. There is some competition and pricing is going to be tough (since Serverless is free)
[1] https://serverless.com/
[2] https://apex.run/