Revit is the best but most companies (small) prefer SketchUp simply because of its low cost. CEOs of those companies don't really care if their employee is having a harder time in Sketchup than in Revit as long as they get the job done using the low-cost (Sketchup) software
You can use both for one project. I recommend using SketchUp for the conceptual design and mass modeling while using Revit to develop a more detailed structural and architectural model for BIM purposes.
Revit is the best but most companies (small) prefer SketchUp simply because of its low cost. CEOs of those companies don't really care if their employee is having a harder time in Sketchup than in Revit as long as they get the job done using the low-cost (Sketchup) software
can they both be used for one project or only choose one software depending on the complexity of the project?
You can use both for one project. I recommend using SketchUp for the conceptual design and mass modeling while using Revit to develop a more detailed structural and architectural model for BIM purposes.