Notice: This has been cross-posted to another website, and re-worded

I currently work in the eCommerce industry, and have hands-on experience building up a Shopify site from the ground up. As I watch all of the developments that Shopify makes both from a technical development standpoint and logistical standpoint, it becomes more and more clear to me that Shopify can begin to take on Amazon directly.

The introduction of Shop app, which aggregates all shipments into a single application including those outside of Amazon, also allows users to browse products from any particular Shopify store. The app also notifies you of any shipping updates, and when packages have been delivered.

From a technical standpoint, Shopify's main attractions come down to a few things: order management, credit card processing, customer management, and plugin integrations. This is the core of Shopify's platform for both larger and smaller businesses. Though due to Shopify's requirement of using their CMS to serve your content, enterprise users have to look elsewhere in order to build something called "headless builds", which essentially use alternate CMS mixed with Shopify's CMS to continue serving their content.

There are a few companies that make such software in order to build out a fully custom site while still using the Shopify platform as its core, though at the moment they are a little 'hacky' but still fully functional. Given the interest in Shopify's platform at such a high level, they are very likely working on their own headless framework which could allow for 1) mainstream stores to integrate their existing platforms into a unified Shopify marketplace, and 2) to allow stores to build out fully custom websites using the Shopify platform at its core and also enroll them into a unified Shopify marketplace.

Amazon has mostly become a front for cheap Chinese-made products, laden with review manipulation and questionable product quality. By instead bringing large brands on board with a unified Shopify marketplace, those stores can sell quality products backed by their brands which can gain trust from customers, and will give rise to smaller brands that may have been unnoticed by larger populations.
[ For example, I recently bought a pair of shoes from a very popular Shopify store: they represent quality, comfort, and eco-friendliness. I personally find myself more willing to spend money on quality products from companies I know I can trust. ]

What's everyone's thoughts? Are there any general problems that could come from Shopify trying to jump-start a full-blown marketplace? Do you think that companies would be willing to integrate their ERP's and CMS's with whatever API's or headless framework Shopify decides to build out?

I am mulling over starting a side business that would involve selling physical products. I would like to set up a web store for this, but want to keep the amount of web development I have to do to a minimum. I would also not like to invade my customers' and potential customers' privacy. Can anyone recommend a way to approach this? I'm a software developer, but don't do much web development and don't really want to do development for this project beyond just getting the site up and running. What options exist for setting up a simple web store?

I've done a search and see things like Shopify. I've heard of them and get the impression they're reputable, but other items in my search seemed kind of scammy. Are there things I should look out for in this space?