Parsing RSS on the client or server side?

Question

PHP

Good afternoon.
For a long time I was looking for an RSS feed parser for javascript, but I did not find anything adequate. Most of them still process RSS on the server side, for example through the Google API.
Why didn't a good library for RSS parsing appear during the long existence of RSS? Maybe this is considered bad practice?
What is better and more correct: parsing on the server or client side?