Really well written web form applications were a delight in 2001 and a large improvement over conventional applications written in Windows. It helped that application data was in a SQL database, with a schema, protected by transactions, etc as opposed to a tangle of pointers that would eventually go bad and crash the app -- I made very complicated forms for demographic profiling, scientific paper submission, application submission, document search, etc. If you did not use "session" variables for application state this could at worst cause a desynchronization between the browser and the server which (1) would get resynchronized at any load or reload and (2) never get the system into a "stuck" state from the user viewpoint and (3) never lose more than a screen full of work.

Try some other architecture though and all bets were off.

Amazon's web store looked and worked mostly the same as it does now, people were very impressed with MapQuest, etc.

Applications like that can feel really fast, almost desktop application fast, if you are running them on a powerful desktop computer and viewing them on another computer or tablet over a LAN