The simple answer to this is it is an app-specific feature. Many of the native and installable apps in Ubuntu support it, but some don't.
Nautilus (the file explorer) supports: right-click on the folder you want in a tab and select 'Open in new tab' (or you can hit Ctrl - Enter
The default text editor in Ubuntu automatically opens new files in a new tab.
All internet browsers that I've used, including the default Firefox, allow tabs in the usual way.
Gimp (graphical editor) opens new images in a sort of tab - there's a thumbnail image at the top to toggle between the selected file.
The major omission is LibreOffice which does not support tabs (for any of its features - ie Writer, Calc, Impress and Draw. It looks from this 2-year-old forum answer https://ask.libreoffice.org/t/opening-multiple-files-in-tabs-optional-function-or-extension/61520 that it's been requested several times previously but not implemented - so that's probably the main one that will cause annoyance, and I doubt it'll be introduced if it hasn't already. I don't know if other open source / free office suites offer this option but please post back here if you find out.