This will probably sound more cynical than it's meant, because I do admire this, but here we go anyway - Whenever I see these impressive-looking online data visualisation projects, I think: What would be interesting - and/or convincing - would be case studies written by experienced GIS people showing how and why they would use this (as compared with other offerings).
Because there are quite a few data visualisation options around these days, many re-imagining subsets of standard GIS functionality from 20+ years ago, into their own online, collaborative, friendly UI (<-- what Microsoft used to call "a wizard"). It's very impressive but at the same time, the unique contributions of such projects are often in the areas of visualisation and UI, rather than in the area of geography. Which are important in their own right!, but will not necessarily be the primary consideration of some categories of user.
At least for static representations, you can get some amazing quality GIS visualisations from QGIS with minimal experience and a bit of work. Paid online GIS visualisations have to compete with some pretty good open source stuff that is often enough for a project's needs.
Modern QGIS is very good. As a former professional turned casual home user, it covers my all requirements personally, but on the other hand there is certainly room for other options in the industry.
On the other topic of online offerings: Putting performance aside, a significant business objection to online GIS - especially regarding large or long term projects - is in the notion that it transfers (some) custody, security, continuity, redundancy of, not just your work, but also your tools, to a 3rd party, making your access subject to the ongoing wellbeing of that 3rd party enterprise.
i.e. My business requires certainty that, should the need arise, I will definitely be able to access the entire functionality over all working files, 5+ years from now, regardless of what happens to 'FancyMapsWeb Inc.' over the intervening years.
Yep. This is what makes QGIS such a great option. Being open source means it is both free and you can easily get your hands on old versions should you need them.
It’s success comes from having a good enough GUI these days.
I think the win here is where people who are not GIS professionals can use it to create stuff rather than waiting a month for their org's GIS team to get around to it.
Because there are quite a few data visualisation options around these days, many re-imagining subsets of standard GIS functionality from 20+ years ago, into their own online, collaborative, friendly UI (<-- what Microsoft used to call "a wizard"). It's very impressive but at the same time, the unique contributions of such projects are often in the areas of visualisation and UI, rather than in the area of geography. Which are important in their own right!, but will not necessarily be the primary consideration of some categories of user.