Telescopic sights are a nice option for hunting and scouting. Cheap sights are not terribly handy, telescopic of otherwise. I've used Leupold telescopic sights in some of the most rugged conditions I care to encounter, and they've remained as functional as the firearm they were mounted to, despite dings, abrasions, impacts and the ravages of adverse atmospheres. I am a more efficient and proficient shooter using telescopic sights than without.

Iron sights are not obsolete, even at long range. I believe it requires greater skill and experience to be as proficient with iron sights as with telescopic sights, but then again I've always been an advocate of practice. At the range I have no trouble shooting out the 1" bullseye with a few magazines of 22 lr in my Ruger 10/22, once I've settled into the groove and got acquainted with my sight picture. That is really what telescopic sights facilitate is the sight picture. It isn't about the maginification so much as the precision and the focal parity of the sights with the target. I can probably shoot my hunting rifle more accurately offhand with my sight set at 4 power magnification than at 9 power, for a number or biomechanical reasons.

The majority of service firearms aren't going to be equipped with telescopic sights, and that's another very good reason to practice shooting with open sights more. On a rifle a modern telescopic sight is not significantly encumbering, so my preference would be to use it if I have it, but on a pistol, there are times when telescopic sights would be debtrimental to bringing the arm to bear on target expeditiously. A hunting pistol can benefit from the addition of a telescopic sight in the intended application, but for use as a self defense weapon, it is likely already marginal to begin with.