At a bare minimum you need a complex database structure to support products, stocks, orders plus the pages for browsing, searching, shopping, ordering, tracking, then you need user accounts, integrations with payments and shipping, a transactional email service etc.

Well, sure. You'll also need a filesystem to run it all on, cache memory with LRU replacement, a router, power and air conditioning, and lots of other stuff. The question was, what's an easy way to do all that that's ready to run. I've set up a couple different e-commerce sites on Wordpress and it's easy and flexible; everything you listed does need to happen, but it's behind the scenes of the plugin installation. I genuinely don't know of a turnkey solution that's easier, although I'm happy to hear about them.

I mean, Wordpress started as a blog. Linux started as a terminal emulator. The question is how well does its current state fit the current task at hand.

There are WordPress plugins that attempt it

Why do you say "attempt"?

it’s usually more for people who use it mainly as a blog/CMS and want to sell a couple of things on the side

So, I run a dedicated site that sells a few thousand items based on Wordpress+Woocommerce; it's basically a hobby, but if I wanted to be serious about driving sales one of the most important things would be the ability to customize landing pages, test out different layouts, make changes, etc... basically, the ability for the software to function as a CMS would be key to what I would want. Being "primarily" a CMS product with selling products as secondary, for me, works better than the other way around (primarily a product-listing-and-selling software with editing pages and layouts as secondary).

I wouldn’t use them for a large shop.

Depends what you mean by "large." Performance is probably the biggest issue that would make me hesitate to go for Wordpress+Woocommerce beyond a certain scale, but as I say I'm running a moderate-scale e-commerce site on Wordpress right now and I've generally been very happy with its tradeoff of "ease of setup" vs "customizability and extensibility for fancy stuff" vs cost.