I, as many, thought the custom skins were too small. Turns out you can make everything scale better by using Windows' own compatibility settings.
The easiest way is to have a thumbnail for VLC on your desktop. Right click the thumbnail -> properties -> compatibility. Under this menu there are two options you might need.
First: you can press "Change high DPI settings". Cross off all the boxes in this, and set the bottom drop-down menu to "System". If this is not available, you'll use
the Second method: from the Compatibility menu, choose "Change settings for all users". This is where you'll do the exact same steps as in the first method, but it will be system wide instead. The next time you run VLC, the scaling should have changed. If it hasn't, you might want to check your general scaling settings and adjust them.