Yes you are right, usually linux users that are not in IT have no choice but using bad microsoft computers (or Apple for designers/upper upper management) when they are employees.
But if you are general manager, or an independant contractor, you do whatever you want, and I have been on Debian, Void since 3 years now and it is just great.
People complain that “your files are not compatible” (i.e.: their excel version can not open a moderately complex xlsx file), and you use stupidly dumb webapp for Outlook and Teams, but otherwise if you don’t need to commit for a specific software (built for windows or mac, like Adobe suite, 2D or 3D CAD softwares, some kind of old school ERP or CRM), you are all good. Basically everything done by management staff can be done using LibreOffice.
The “cloud revolution” at least has given us this good result : you can have basic business utilities solved through a webclient, hence GNU/Linux OS is ok to work with.
Libreoffice suite allows you to export any document in pdf. Libreoffice Draw I use to edit pdf content. PdfArranger is a very nice tool to change the structure of a pdf (like adding a pdf file to an existing pdf, or deleting pages, you see all the pages at once on the screen and can see the content when you zoom, very intuitive). When I need to add signatures or raster pictures with transparency, I open the required page on Gimp and “File->Open as layer” the picture. Usually it works with Draw directly.
I have been working several years like this and it is pretty much a no-brainer now.