There's a substantial difference between competition and real life.
Besides the inherent weakness I see in the thumb method, the photo above shows the shooter (no offense if it's you) concentrating on looking down at the speedloader & totally ignoring whatever's in front of him.
Correctly done, the rod-smack occurs at a high enough elevation to allow the user to positively bang all empties out and reload while still maintaining a view of what's going on out front.
Cover's a factor, but aside from that, positive ejection and avoiding losing sight of the threat are both important to me.
Shooting at paper, it doesn't matter where your eyeballs are while you're reloading, but when the "paper" is shooting back, or advancing on your position, or moving behind their own cover, it's good to maintain awareness during a dynamic encounter.
The Air Force taught me the thumb method in 1972.
I used it through four years of quals with them, and starting my civilian career in '76.
I was well-versed in thumb investment, and still considered the rod-smack such a light-bulb epiphany when I was first exposed to it that I adopted it immediately & taught it later on when I was a firearms instructor for my last PD. Along with other instructors.
From about '82 till revolvers were finally banned in favor of autos in '88, we taught it.
Ayoob taught it, Farnam taught it, Tueller taught it. Those are three I personally knew back in the old days.
Other professional schools/instructors were teaching it nationwide.
My PD was the second largest in my state, the rod-smack was all over the place around here.
Many competition techniques are developed strictly for competition, and work well in competition.
Some translate into the real world effectively, some don't.
In my case, and you make your own choices for your own uses, I prefer a guaranteed positive method that covers all swing-out DA revolvers equally well, irrespective of frame size, brand, or rod length.
The rod-smack gives me that, the thumb simply doesn't.
Regardless of how much I may practice the thumb, all it takes is one tight case to disturb my "thumb routine", whereas punching that rod on every reload will remove all but a seriously stuck case right along with the easy ones.
I don't use light target loads for carry.
In the magnums, for instance, it's not totally unusual to get one (or six) tight empties that need some "Get the flip out NOW!" force provided by smacking the rod, as opposed to a lesser level of leverage provided by my thumb.
I've adapted rod-smack slightly in using the other hand, but it fits my coordination better. It does involve switching hands, adding fractionally more time, but that's FRACTIONALLY more time, and unlikely to be significant in real life.
Use whichever fits, I'll stick to the smack.
Denis