Web disadvantages

Brittle When browser-vendors created new vocabularies, those vocabularies would make pages 'break' in competitors' browsers. The W3C's efforts to call a halt to new vocabulary development mostly froze a set of compromises in place.
Underpowered HTML never really did all the tasks developers wanted it to do. Part structure, part formatting, this creature of convenience wasn't always convenient.
Server-Centric Because Web browsers provided only a very limited set of capabilities for processing information in the browser client, servers had an enormous amount of work to do.
Focused narrowly on computer-human communication The formatting and document description aspects of HTML made it nearly impossible for automated tools to use HTML to communicate with each other.