In ArcGIS Pro there are many tabular items that require a "click in" or F2 before a new value can be pasted.
Some also require a click out or ENTER to capture the value.
When editing in Attribute Tables, Domain & Sub Type entries and other functional locations you have to select a cell, then click into it or hit F2 before you can Copy or Paste a value.
Compared to ArcGIS Desktop's Catalog or ArcMap this behaviour by Pro slows you down.
An example is the difference in behaviour between configuring domains in Pro vs Desktop Catalog.
In Desktop Catalog you can very quickly copy & paste a few new values from Excel.
In Pro you have to click into each field you want to paste into or copy from.
Doing this in a complex workspace with many domains where only a few items need to change in various domains can quickly add up to a lot of wasted clicks in Pro.
Another example is to edit/update cells in a few rows in the Attribute Table.
In ArcMap you can copy a new value and simply use CTRL+V and UP or DOWN ARROW to quickly finish off quite a number of rows. This is not possible to do in Pro and requires the use of the mouse and/or use of F2 and ENTER to cycle through a few fields.
In addition to this many tabular cells in ArcGIS Pro do not have a context menu (Right Click menu) so only option is to use CTRL+C, CTRL+V, etc.
In ArcCatalog in some cases you can only use the context menu for Copy & Paste and not keyboard shortcuts. This leads you to end up using Mouse to copy & Keyboard to paste.
These differences in process execution time is particularly apparent in job shop scenarios where you have many small datasets to manipulate. Using geoprocessing tools for each one will typically take even longer for reasons such as client's new data is supplied in a form not suitable for geoprocessing tasks, etc.
Using multiple geoprocessing tools in Pro in quick succession is also time consuming due to the continuous rendering of the "beautiful" GUI.