Do You Really Need a PDF Library for Simple Conversions?

Working on a side project recently, I needed a way to let users upload documents and get them converted to PDF, or sometimes the other way around, PDF to editable formats. My first instinct was to look into libraries like pdf-lib, pdfkit, or even spinning up a LibreOffice headless instance on the server for conversions. That works, but it adds a lot of overhead for what was honestly a small feature in a bigger app.
For quick testing and prototyping, I ended up using FreePDFConvert (https://freepdfconvert.io) just to handle conversions manually while I decided whether it was worth building conversion logic into the backend at all. It runs fully client side in the browser, no install, no signup, so it was useful just to sanity check output quality (formatting, font handling, etc.) before committing to a library or self-hosted solution.
A few things that stood out from a dev perspective:

Conversion speed was fast even for multi page documents
Formatting stayed mostly intact when converting scanned or text heavy PDFs to Word
No weird watermarking or forced downgrade after a few uses, which a lot of "free" tools do

If you're building something where PDF handling is a small part of a larger app, it might be worth testing your expected output against a tool like this first before deciding to add a full PDF processing library or server side dependency. Sometimes the added complexity isn't worth it if your use case is simple, and sometimes it very much is if you need automation, API access, or need this to run without any external service.
Curious what others are using for PDF handling in their stacks, especially if you've dealt with headless LibreOffice or serverless conversion setups. Trade-offs between build vs use-an-existing-tool would be a good discussion.