I disagree. LaTeX is very good at layouting test, and can also (reluctantly) put figures into the text. Anything else is a huge hack (like TikZ), and one constantly runs into crazy limitations such as the fixed-point math and the lack of a decent visual editor. Slides should never have paragraphs of text on them, so the layouting is not very useful, but the other limitations are very annoying.
TikZ and Asymptote are more or less the only general-purpose modular illustration markup languages we have around. Anything better is welcome, but graphical editors are not an alternative in some cases.
The whole point is to focus on the data and how it is connected, not on the rendering. You want the ability to model your figures as a program which can be tweaked and extended as needed, used as a framework throughout the deck.
Drawing every single figure by hand with a graphical tool is not at all something I'd even consider.