I’d love to use FOSS exclusively, but it’s frankly impossible under certain conditions.
Acrobat is a must. Alternatives such as Evince or their back-end library can’t handle the following situations:
Formulars, such as calculating a sum based on the preceding fields.
Field formatting, such as appending .00 to a currency amount conditionally upon field unfocus.
Everything related to government forms due to the above.
Large password protected PDF files.
Besides, if anything is wrong, you’re on the hook for not using Acrobat.
Microsoft Office is a must.
OnlyOffice, WPS free as in free beer, and especially LibreOffice can’t handle anything beyond intermediate documents.
OnlyOffice and WPS struggle with more advanced features, such as forms.
LibreOffice notoriously renders Microsoft Office documents incorrectly in my experience.
Everything in LibreOffice except LibreOffice Writer feels unpolished to me, particularly LibreOffice Calc.
OnlyOffice supports only few fields.
OnlyOffice permits free form input for fields that aren’t.
Adobe is a must.
Alternatives don’t integrate as well with each other as Adobe apps.
Rendering whatever you have to import that into another app is a slow workflow, compared to Adobe Premiere that embeds Adobe After Effects sequences, for example.
Alternatives don’t support scripting sometimes. Scripting is necessary to speed up slow and error-prone manual processes.
Adobe has a rich plugin ecosystem, whereas alternatives don’t support plugins at all, or don’t have any notable plugins.
Alternatives don’t support Adobe file formats as well as Adobe.
You face similar problems to Adobe with alternatives, such as:
Inconsistent keyboard shortcuts.
Inconsistent file format support.
Overall, I’d love to, but can’t. FOSS isn’t good enough.