Cortana takes up a lot of screen space in the taskbar, but if you're short on screen space, you can always disable Cortana's search box.
To adjust the assistant to a pop-up, right-click on the empty search box, hover over ‘Cortana,' and select ‘Hidden' from the fly-out menu. By selecting the ‘Show Cortana icon' option, users can keep Cortana in the taskbar as a (much smaller) standard icon.
Microsoft separated Cortana from the search box with the Windows 10 April 2019 Update, placing its icon to the right of the box. The search box can still be hidden by right-clicking it and selecting 'Search' then 'Hidden.'