Yes, small Icons are normal for "parts" of the client such as the File Icons in the Local and Remote Windows, though that's not even true because they are actually BIGGER because "text" is also being included to be able to click on. But yes maybe certain icons can be small such as shown in the below pic for Windows File Explorer; however, comparing File Explorer as well as FileZilla Icons, you can see they are MUCH bigger than WinSCP's file Icons.
As someone else said, we should not have to be "conducting surgery" just to click on common used buttons of a client. We need up to like TRIPLE the Button Size... and that's just for us with good eyesight. You need to be able to go MUCH HIGHER for those with different eyesight.
Otherwise, you have a good looking and working client... But, we really need this fixed.
I can't use FileZilla because after their many years they STILL don't have Navigation Bars for Local and Remote windows, which is one reason why I need WinSCP's icons to be LARGER, cause I'm going to be clicking some of them A LOT.