[HillRat]

There's a real "it depends" flavor to any answer you'll get. If your feature set could be handled by off-the-shelf Magento with a couple of plugins, then, sure, you probably should have gone that way. But if you have unusual needs -- and Magento's rigidity means it's not hard to hit that wall -- then either you create massive technical debt kitbashing Magento or similar, or you go with one of the high-end headless systems, which are both expensive and still require you to build front- and backend solutions around them.

In turn, depending on your needs and the regulatory regimes you're working under, you may find that you could have saved time and money going with an industrial-grade solution that can seamlessly handle taxes, accounting and revenue recognition, multi-vendor logistics, credit/refunds, reverse logistics, etc. (there's a lot of etc.!), but that could be overkill for your requirements. I've seen SMBs with small digital teams build and run bespoke e-comm solutions handling all their needs (and more effectively than trying to fit a commercial square peg into a round hole), but the more complex and general their use cases, the more trouble they tend to have, especially when they get into multi-stakeholder retail scenarios (e.g., things like splitting a net-90 invoiced order between multiple future dates, vendors and warehouses, and logistics providers, while acting as a subledger that can handle revenue and income recognition properly).

[JLuterek]

This seems like an old view of the current ecommerce landscape. Sure Magento is still an option, but as you pointed out it should only be considered for basic implementations where it can be used off-the-shelf with minimal customization.

Building a fully custom solution is the most expensive option today and really unnecessary. There is no reason to build your own product management system when so many flexible options exist. Just as I would never recommend building a server and push people towards containerization and the cloud, I recommend finding components that can be leveraged to streamline the custom build.

In terms of high-end headless systems, the market is large and growing. Some leading composable commerce SaaS offerings can offer free tiers and have pre-built front-ends and integrations.