This seems to keep coming up in the never ending debate, and I look at it this way... there have been MANY years, even decades of breeding involved in producing HIGH potency plants in the PHOTO realm. If you can breed to improve the levels in photo's it should not be that hard to do the same in the AUTO realm, imo...
Look at it this way...somewhere, sometime somebody decided they wanted a plant that would not require the lights to be changed, or wanted a fast (pre-PHOTO) harvest outside, and decided to breed the TRAIT of ruderalis(spelling?) finishing within a LIFE CYCLE independent of LIGHT CYCLE. Did the ruderalis affect the THC? Most def. But they also know they can, and ARE in fact breeding out this UNWANTED trait of the ruderalis... And imo, they are doing a HELL of a job of it, and I feel also, a BETTER job of it given the relatively short amount of time they have had to do it...and it can only continue to improve...
Can the most potent photo strain beat out the most potent strain of auto in existence at this time? Most likely, probably certainly, YES...but that doen't have to mean that someday it WON'T...
I have smoke many auto stains, and even grew some of my own, and I was very impressed with them...they got me BAKED as hell. On the flip side I have smoked a LOT of mediocre photo period bud, and autos too, it all just boils down to preferences and finding what YOU prefer to GROW and SMOKE...that process has NOT changed at all...If you tried auto's and failed, it MAY be that is because you were used to growing photos, and there are MANY differences in the techniques of growing Photos and Autos to their potential...I would guess the failures stemmed from, yes, inferior autos, but ALSO, it can't be denied that many case where just those trying to grow them too much like photos, which does NOT lead to a GREAT auto being raised to it FULL potential...