Never had a Tasco fail yet, have had one fairly pricey Simmons 15X bite the dust after about 8 years and thousands of rounds on a 22-250 varminter. Will no longer hold zero. Cost around $150 on sale, maybe 18 years ago?
Only scopes that ever failed, (mostly trashed reticles or lost ability to track), were cheap Bushnells. One of those was dropped and died on the spot. On the other hand, have two 4x12x40 Banners w/BDC, that are still working fine after 25 years.
One Jap Tasco, a 6x24x40, has been on the same heavy barreled 25-06 since day one, no problems at all and that rifle has also been heavily used. Bought that scope new in the mid 80s when I built the rifle.
Current Tascos still working fine, are a 3x9x40WC, on an 8x57 sporter, probably 15 years old; 2.5x10x42 mildot, on a 223 heavy barrel; 6x18x44 (two), on varminters (22-250 and a .224-06); couple assorted Tascos on rimfires. Also have several old steel tube Weavers, no problems other than the K2.5 will fog a bit. That one is over 45 years old, the others not much fresher.
I have one Leupy Vari X II, on a Ruger M77 tang safety in 25-06. Looks like it's been rode hard and put up wet, still very clear, works as it should. Figure it's at least 25 years old?
Newest scope is a Bushnell Trophy 6x18x40, on a 243 varminter. Only a coupla years old, but a buddy had two of them on his varminters and never had any problems. He was a life-long Leupold fanatic, made me chuckle when he bought those Bushnells.
BTW, there is nothing much harder on any scope, than a semi-auto centerfire. Mini 14s are especially noted for killin' scopes dead, even expensive ones. Most scopes cannot hold up to the repeated bolt cycling and resultant jarring effects.
The average deer rifle might get fired a dozen or so times per year, while varminters will see hundreds or thousands of rounds in that time period. A scoped Mini might also see that many rounds, if one has enough time and ammo, but firing cycles are much more rapid.
The old adage still holds true: Buy the best scope you can afford and you'll never be sorry.