Descartes underwhelming

Widely viewed as one of the great philosophers of history, and often as the "founder" of modern philosophy, we have Rene Descartes.

I am underwhelmed.  He is of course famous for "cogito ergo sum," "I think therefore I am."  Anything else?  Well of course he gets there by questioning (doubting) everything -- now what teenager hasn't done that many times?  And then from there he concludes that this thing that thinks is the soul, that others besides ourselves do likewise, and that God exists and God gives us these souls.  (Most of the rest of this is not payed much attention to because it is pretty obvious to even the most determined believer that the argument is flimsy).

I think Descartes proposition is popular because it has an emotional appeal -- at least we can be "certain" that we exist, or something about us that thinks exists, to be more exact.

He doesn't accomplish this.  His thinking, and my thinking, and your thinking, proves nothing exists, not even thinking (what exactly is a "thought" anyway?).  The idea is that if there is an activity then I guess there has to be something doing the activity.  Here the activity is thinking, so something doing the thinking has to exist, and that something is obviously (really?) me.

No, Descartes just thinks he's thinking.  He doesn't know it, nor can we.  We don't even know that thinking is an activity at all or if it is that it needs an agent to be doing it.