I was thinking if I had a list in Modern UI and then use JSON column formatting. Does it support paging or sorting through the items?
Thanks in advance.
If you have formatted your column using JSON formatting, it will support Sorting and Filtering.
See below image, "Container Content" column is sorted in descending order and you can use Filter by option to filter the rows based on column value.
SharePoint Online Modern Experience View formatting does not supports Pagination as of now.
There is a SharePoint UserVoice related to this. If you want Microsoft to implement this functionality then you can vote on the idea.