Buying a scope for a hunting rifle is pretty straightforward: determine the terrain you will be hunting in, and the distance that you typically take your shot at, and buy a scope of suitable magnification.
Hunting prairie dogs across an uncluttered plain calls out for very high magnification. Hunting whitetail in the Northeast probably means dense forest among the hills, and the shots that present themselves to a hunter will be much closer; less magnification is better for that. Variable magnification scopes give hunters extra versatility, but even with modern technology there are real and practical limits to what a scope can do. Shooting in low light (when hunting coyotes, for instance) calls out for an illuminated reticle, which is a more common feature in the last 10 years.
A scope for combat has different requirements, because there are so many different kinds of combat.
Everybody likes new things. And the advertising practices of the past 50 years have deepened and solidified our hunger for new things beyond the limits of common sense.
How else to explain the mad dash to ditch a perfectly good smartphone when a new model (that is functionally 97% identical to the old model, and light-years better than the phones of 5 years ago) is released? IT managers were not hallucinating when they observed an increase in broken phones when a new iPhone was released. You can’t have bread & circuses without the bread.
Guns are not immune to this trend. When something bigger/smaller/faster/shinier comes out, we all salivate a little. Senator Phil Gramm once described the size of his arsenal as “more than I need, but not as many as I want”. A smart consumer should mitigate his/her urge to acquire new hardware with the knowledge of: budget priorities, how easy it will be to get ammo/parts/accessories, reliability of warranty coverage, and whether or not the gun is chambered for a caliber that he/she already supports. No one is saying that those are rules to adhere to at all times. But you need to weigh all the factors against your personal situation before deciding. Bullets without a gun to shoot them are as useless as a gun with no bullets.
If you are going to do any long-range hunting, or if you want to improve your marksmanship beyond 50 yards, you need a spotting scope. You can’t learn & grow your skills if you can’t see what your current performance is. Not knowing where your last bullet hit will hold back your development as a shooter. And running downrange to examine your target repeatedly is going to tire you out and piss off your fellow marksmen.
A binocular is fine out to 50 yards, but beyond that distance the lack of magnification is a problem.
And, no, the scope on your rifle is not “good enough”, even if it is a fancy German brand. It doesn’t have enough magnification, and you don’t want to get into the habit of aiming your gun at everything that you want a closer look at.
If you want to improve your skills with a long gun, and get your guns sighted in correctly, you need a spotting scope. In optics, you generally get the quality that you pay for. Below, I will address some of the considerations that you need to think about before choosing a spotting scope.