Problem with Current Dragon (long read)
So as we know, the first dragon buff is currently "+8% AD/AP", which has become 6% on PBE. I'm not going to discuss the numbers, my issue is the fact that a global AD/AP scaling buff is unbalanced because it favors champions that build two specific stats. Champions that run on AS, Apen, Mpen, Crit, and of course tank stats don't get very much out of this buff, and since in most games both teams will end up with at least one dragon, this is an indirect nerf to all champs that don't stack straight AD and AP.
The flat Apen/Mpen buff we used to have worked much better because it increased all damage (except true damage) regardless of what stats are built. I can't remember the details of how flat Pen works (like whether it increases the damage by the same amount regardless of enemy resistances), but it does seem like it increases damage fairly consistently for all champs.
Why is this important? If you jungle and a dragon, it's unfair to get almost nothing out of it because your team picked champions that don't synergize with it. This is especially true if you solo dragon; you've lost a lot of time and health to get the buff and you've put yourself a little bit behind, and your team doesn't get anything out of it.
The second problem is that flat Pen is useful all game, whereas %AD/AP scalings are more useful lategame. If you take an important objective in the first 15 minutes of the game, and all you have to show for it is single-digit stat points on each carry until they get more items done. This is compounded by the fact that if you're a Devourer jungler, the attack speed and the stacks get nothing from that buff, so the first dragon doesn't even help you (and not to mention Juggernaut, especially since a lot of tanks actually benefit from Pen).
If dragon had worked like this last season, madstone Godyr probably wouldn't have been a thing because a tiny buff like that isn't enough to keep the lanes alive so the jungler can afk farm. And perhaps Riot is attempting to kill that strategy (they did a good job fixing the toxic characteristics of Flare while keeping a scaling jungle item), because even though a lot of champs can solo dragon early now, they're better off ganking lanes or even farming because the first dragon buff just isn't worth falling behind for. Perhaps that's good for the game, but in soloq jungling can be painful (your laner either doesn't notice you ganking or doesn't know not to chase under the tower, pick one) and being able to influence the earlygame through solo dragon control was a lot more consistent and enjoyable than relying on randoms.
So bring back the tier 1 flat Pen buff. Balance the numbers, but make it Pen again so that it actually does something in the earlygame when ADCs aren't juggling swords and all the other damage comes the base damage on abilities. Currently all the first dragon buff is good for is rubberbanding, because odds are both teams have it by the time it becomes relevant. Getting that first dragon is fun, and it shouldn't mean falling behind because the enemy jungler was actually doing something useful.