I get where you're coming from in principle, but I'm not sure to what audience this actually applies. If you just want a laptop that can run the software you use, both are adequate as tools. The Framework's greater flexibility only applies to making changes to the tool itself, which doesn't matter if you didn't need to change it to suit your purposes. (And I say that as someone who has built their own Linux & Windows PCs from parts since high school, because I know I'm not the target audience for a Neo)
It's like I consider my Dewalt power drill a very decent tool because it has exactly the modularity I need -- it even has interchangeable batteries -- and it wouldn't even occur to me to call it an outright appliance even if another power drill offered more customization for some niche use case. The Neo is an adequate tool for many people even if other tools do offer more customization or maintainability.
This would be a much stronger argument against using an iPad for productivity, because many people simply cannot run the software they need, or only at a significant expense to productivity and quality of life. I use iOS devices only as communication and media terminals, and even then I would struggle to call them appliances, they're still tools for their particular tasks.