What would be a fair comparison of various PDF parsers available in the market now?

Key Considerations and Recommendations:

For general-purpose, high-performance PDF processing (including complex PDFs): PyMuPDF (fitz) is an excellent choice. Its speed and ability to handle complex layouts make it a strong contender.

For modifying or manipulating PDFs (merging, splitting, etc.): pikepdf and pdfrw are your best bets. pikepdf is generally preferred for its ease of use. pdfrw is more low-level and powerful.

For simple text and metadata extraction from relatively straightforward PDFs: PyPDF2 is a decent option. It's pure Python, so no external dependencies. However, it may not be as robust as PyMuPDF or PDFMiner.six for complex PDFs.

For extracting data from tables in PDFs: pdfplumber is specifically designed for this and does an excellent job.

For robust text and data extraction, particularly when you need more control: PDFMiner.six is a solid choice.

Which one to choose?

Most common use case (text extraction from various PDFs): PyMuPDF (fitz)

PDF Manipulation: pikepdf

Table Extraction: pdfplumber

Simple PDF text extraction (pure Python): PyPDF2 (but be aware of its limitations)

Remember to install the library you choose using pip install <library_name>.  For PyMuPDF, you'll likely need to install the pre-built wheels for your platform to avoid compilation issues.  Refer to the library's documentation for installation instructions.