I"m going to argue a different way in favour of the 'JAMstack'; I hate marketing buzz, but whatevs.
This is the business value from what I can see; I'm newer to SPGs, so I could be wrong, but it's my current opinion.
Static sites do the following:
They are very very fast. Most WP sites that are setup on a budget are not fast and actually require hiring the right developer, not just 'any' developer to get it to serve quickly. Not the case with SPGs, if you can write HTML, CSS and JS then you are booming; it's very hard to make a slowly served site I'd wager.
Clients think they can just slap in a plugin and get a rocking; this is why wordpress is slow and they don't know who to call or what to do and they are channelling money into SEM and SEO and losing money there hand over fist; this is a huge value.
The code tends to be more easily read. This means if they call me up and say 'hey Roger can you create an xyz or do xyz', often I can do it in an hour or so and it's still fast and it's still easily read by the next guy.
Backups are built into the system al a github/git.
Security issues are basically null. In comparison to any surface like WP, effectively using Hexo, et all is a zero risk scenario.
Price. Outside of tools like Contentful and their type, the pricing is as close to $0 as you can get, which means I'm getting the lions share and that is good for me and good for my investment in good customer service.
With Netlify and CloudCannon content management is included and no longer an issue of paying some over charging headless CMS provider extortion rates to just serve content.
Most SPGs come with Let's Encrypt and CDN built in and not as a value add either.
Honestly I'm very happy to have finally sold a client on a SPG and while down the road they may need to include a more diverse solution; today it'll be a great launch site for them handling so many potential scenarios without additional work on my or their part.
PS. This doesn't at all dismiss wordpress; that would be silly to say one over the other, just simply that SPGs have a ton of value and are very valid from a business use case.
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