I am currently shifting to QGIS from ArcGIS. I know that ArcGIS has this distributed collaboration system which allows multiple users to edit a shared GIS file (after uploading to an ArcGIS portal) simultaneously. I wonder if there are any similar features or plugins available in QGIS.
Have a look at the Kart plugin, it works like Git, but dramatically simplifies the process. The last QGIS Open Day had a nice introductory talk that you can view here: https://www.youtube.com/watch?v=aABc3JrgJUY.
Otherwise setting up an online PostGIS database is fairly straightforward, which can then be added as a "live" layer in QGIS. There is also a versioning plugin for this (though I haven't used it): versioning plug in