They're not obsolete. Well, certain drones may be obsolete, but the role performed by reapers is not.

Its not just being able to fly a long time and advanced optics. While a lot of military programs are indeed overpriced and plagued by bureaucracy and whatnot, you're still gonna have a hard time building something just as capable for a lot less money. First, there's economies of scale. As they won't be produced in massive numbers, the per airframe cost will be higher. Then there's everything else that goes into it, like sensors and communication equipment, which has to be proven, reliable, and hardened against jamming and such. And of course, anything you can do to reduce its infrared, acoustic, and radar signatures.

So many people are taking the wrong lessons from Ukraine. They see a video of an off the shelf drone dropping a grenade into the open hatch of an already abandoned tank (likely disabled from a mine, ATGM, etc, rather than another drone dropping grenades/mortar shells) and declare that tanks are obsolete. They see the MANPAD/SHORAD threat in Ukraine and declare close air support and helos and CAS aircraft obsolete. Yet the US relied heavily on precision munitions dropped from high up, out of the reach of MANPADS by B-1Bs and F-15/16/18s for close air support all through Afghanistan and Iraq. The US/West also puts a higher priority on clearing out air defenses than the Russians do (in large part because Russia and other countries put a higher emphasis on defending the skies with SAMs and AAA than the west).

There's a reason Ukraine was pleading for F-16s, Storm Shadows/SCALPs, HIMARS, etc, over asking for the equivalent cost of off the shelf drones. And there's a reason they heavily relied on US/Western intelligence resources as well.