The idea is that there's no trust required: My app handholds people through the process of setting up on AWS/Azure, then it uploads to their account via their API key. So if i close up shop, they wouldn't even notice (although they might notice a lack of new features after a while).

So yes they'd be paying me and the server. However the server fees would be cents a month. I would aim to present this as a strength to the user: you get billed direct by AWS/Azure because you're not at ransom to me - you hold the keys to the kingdom.

I suspect you're right though: Technical people will DIY, and nontechnical won't care, and will simply use Wordpress (it's the IBM of blogging: "nobody got fired for buying Wordpress")