I think both play a role. Competition pushes scientists and brings out their best. Given the limitation of terrestrial resources, collaboration is critical to get more bang for the buck spent on science globally.

The uncertainty of dark matter and energy makes it more fascinating!

We will realise that with the expanding universe, it will be impossible to detect life elsewhere, even if it exists, as the distances are ever increasing and become in-surmountable. We are lonely and will remain so.