I will add my vote to those suggesting that the vibe in this thread has departed from AFN standards. One of the reasons I am here is that over aggressive argument is not tolerated. Nuff said on that.
As to the topic raised by the OP, I have used jiffy pellets (pucks, whatever), and they work fine. I move them to either the final pot or an intermediate insta-tranplant pot of some sort as soon as I see the tap root emerge from the pellet. I don't like letting the tap root start searching for dirt that isn't there.
The advantages of pellets, IMO are mainly that watering, temperature, and RH are more easily controlled in the small "container", and for limited grows like mine, I do not want to waste time with final containers waiting for a dud to show up. Starting plants on my seedling mat in a domed tray means that I can do however many extras I might need before selecting the girls to be moved to the final pots. The domed tray with heat mat also makes controlling early environment easier than starting in larger or final pots.
OTOH, I could simply plant more than one seed in the final container, and select the best after they show their stuff. That still leaves the watering issue though. Tiny plants do not use much water, and if the medium gets too wet, it is likely to stay that way for quite a while. I may try direct planting at some point, but am in no hurry given my success with other approaches.
I have "transplanted" all of my girls so far, and have to say that if it did any harm, it was invisible to me. I suspect that the experience virtually never resulted in more than a day or two of stall if that. Mostly, it seems to me that growth is going again in ~24 hours. Even with autos, that seems pretty much trivial to me, and it pales in comparison to my other screwups, mostly regarding excess nutes, salt buildup, underfeeding. et bloody cetera.
Bottom line for the OP, the pucks work. Are they necessary? No. Do they have a significant downside? If used with care, I doubt it. Do they have advantages? IMO yes, primarily with the ease of controlling environment including watering, plus avoiding wasting time with duds in larger initial containers.
By the way, the pellets are used and recommended by the gurus on Cocoforcannabis.com, and they know what they are doing. For sure, they know a heck of a lot more than I ever will about this mischief, so my opinions here should be taken as just my 2 cents.
Happy growing peeps.