Sometimes it can be difficult to zoom in close enough to an object in Blender 2.8. A small edit in your preferences is all it takes to fix the slow zoom speed.
One way of fixing the slow zoom speed is to activate auto depth in the top bar menu.
You can access this menu by choosing Edit and then Preferences. In the preferences menu, click on the Navigation button, and under Orbit and pan there’s a checkbox to activate auto depth; enable this.
Auto depth will use the depth under the mouse to improve the viewports panning, rotation and zoom functionality.
If you later find you’re not happy with the change, simply disable it at the same location.
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