Using SSRS to Show Reports in a Web Page

I have an upcoming project at work to develop reports displayed in a web page. I've been pointed to SSRS (or possibly Power BI) to build them but I don't really see the point of using it instead of just using web services to send data out to a Javascript front end.

The requirements include:

1. Sort the data
2. Filter the data
3. Group the data
4. Hide/Show columns
5. Save user preferences
6. Output to other formats (.pdf, .xslx)

I haven't worked with SSRS much so maybe I'm missing something, but it seems that we'd have more flexibility in the look/feel of the page, the functionality, and how the data is loaded if we ignored SSRS and rolled our own with little extra effort.

What exactly would be the advantage of using SSRS in this case? Am I right to want to architect my own solution from scratch?

>What exactly would be the advantage of using SSRS in this case?

It's mostly that you wouldn't have to build and maintain the content in custom HTML and JavaScript. It's a typical build/buy tradeoff, and one that's often driven by the desire to have a high velocity of change, and to enable single person, and perhaps even a non-developer, create or maintain the reports.

Also .pdf and .xslx rendering are non-trivial, and typically require separate design and layout.