You can add (“merge”), remove, delete pages, which is technically editing.
You can annotate the document by adding text, pictures, signatures, checkboxes as well as fill PDF form fields: unfortunately as you noticed you cannot “edit” existing text.
(I initially used the term annotator but it confused people so much that I changed it for edit and editor)
It’s free and does not require an account (I don’t like websites that force you to sign up to do anything)
Disclosure: I’m the solo developer behind it