Well, the tech stack is insane: Some virtual machine running a web browser process running a virtual machine for a html renderer which consumes a document declaration language incorporating a scripting language to overcome the document limitations trying to build interactive programs.
Actually much worse as Microsoft once did with their COM model, ActiveX based on MFC foundation classes with C++ templates, etc.
And to build those interactive programs somebody is trained to use React, Vue, etc. using their own eco systems of tools. This is operated by a stack of build tools, a stack of distribution tools, kubernetes for hosting and AWS for managing that whole damn thing.
Oh - and do not talk even about Dependency Management, Monitoring, Microservices, Authorization and so on...
But I really wonder - what would be more complex?
Building interactive programs based on HTML or Logo (if anybody does remember)?