I learned web dev first by using Geocities and Frontpage, then Dreamweaver. These days I actually get paid to write Javascript (something young me would've found unbelievable enough already), but to me that's still a huge difference from "real" programming, especially in C or assembly.
Web dev (at least the kind I do) is mostly still just declaring UI in a XML like syntax, then wrapping it up in some events and state management. It's not that different from, say, Visual Basic. At its core it's a bunch of event driven reactions and API calls based on UI clicks. Once upon time that was Perl or PHP or jQuery, now it's usually React, but the fundamental process of "declare UI, add event handlers, send to APIs" hasn't changed much IMO.
But an OS? Man, how do you work with memory access? Overflows? Garbage collection? Device drivers? Caching? Graphics pipelines? USB? Lightning? I don't even know where to start with any of that, and an OS is ALL of that and then some.
Mad props, is all I'm sayin'.