I'm sometimes working with data with as much as 250MB in a single HTML file. While it may not seem a lot, 50000 objects within a table can generate an 80MB HTML file.
What makes it even more complicated if you have five or more tables with the same amount of data. The problems start when you have to display 50000 users, 50000 permissions, or any other data type. Even a basic ConvertTo-HTML cmdlet with some CSS can be used and display that data. You see, working with one table having 300 users with 30 fields each is a no-brainer. One of the things I worked on was performance when working with huge datasets. Those search-improving features are just a tip of an iceberg of what was added in the last few months.