Version: 7.4.5.1 / LibreOffice Community
Build ID: 40(Build:1)
CPU threads: 2; OS: Linux 5.15; UI render: default; VCL: gtk3
Locale: en-US (en_US.utf8); UI: en-US
7.4.5-1
One single .odt file with all contents created using Writer built-in editorial tools. No graphics, no formulas created in external formats.
I wonder if printing out document to pdf is guaranteed to deliver pdf of same quality as exporting to pdf.
By whom?
Printing to PDF would use different mechanisms, depending on your OS (e.g., on Windows, you would need special virtual PDF printers), and those different mechanisms would have own methods to convert printing commands into the output.
On the other hand, exporting to PDF also has own settings - see File → Export As → Export as PDF, where the dialog defines things like image quality (unrelated to your question, because of “no graphics”) and exporting of outlines (which would be totally impossible for printed PDF).