You're right on one account, that modern problems started with Sykes-Picot. I'm under no illusions that I blame the French and Brits for that. Particularly, for planting Israel here.
The region had at least one major war every decade since 1948. Go ahead and verify that. Eventually, the British and French influence waned, and American influence waxed.
America's fingers are in every major war in the region since 1967. That's 6 decades ago.
Having said that, the region was mostly peaceful since the crusades and Mongol invasion just under a millennium ago. Yes there were empires fighting (namely Ottomans VS. Memlukes and Ottomans VS. Safavids), but it's nowhere near what we had since the cursed agreement.
Moreover, every country in the Middle East has been in at least one war since 1967 (perhaps except Oman and Qatar, even if they participated in the first Gulf War in 1991). Now, I'm sure not all these wars are American made, but surely American influenced. Again, go ahead and verify that.
In any case, you changed the goal posts. I was specifically talking about Iraq since 2003, and that particular war (and it's results) is squarely American made. There is no way you pin it on the Brits and the French. While I'm no Saddam supporter by any mean, Iraq and the region are far worse since. There are no two ways about it.
So, no, the region has not improved. And for most of the people here it's a trifecta of Western interference (including, but not limited to, Israel and the US), despots, and reactionary movements like ISIS. Those three have devastated the region. And be under no illusion, most people don't see light at the end of the tunnel.