Oh em gee, salt is sewn everywhere in this thread lol.
Umm, G&W on paper does well b/c of really good stats in terms of good juggling and edgeguarding (although aside from fair I don't see him gimping Lucario), and air game.
Lucario thrives on G&W's exploitable difficulty to land a kill move outside of fair, and G&W is going to do all those things to do to get Lucario offstage in a bad angle. It gets more risky to get those in because of the damage output a punish from lucario does at later percents.
Lucario is bad theorycraft material b/c he's imo a punisher primarily, and those chars in theorycraft land are always bad b/c the opponent always magically plays "perfectly". Problem is that most options have cons, and depending on the MU lucario punishes pretty heavily on those, and while his options may not be the best, a lot of them are straight forward in what they're able to punish or not. Fsmash for example covers pretty much every option the opponent has in the air, and it's fairly safe on the ground when you're not predictable with it.
Lucario crunches G&W in a similar way that he does to marth, you have to cover his zoning.
G&W has better CPs, I'd give G&W the nudge on that alone.
Lucario outlives G&W significantly in the MU unless he screws up.
G&W dthrow happens but even with some of Lucario's relatively meh options he's still fairly difficult to read, also grab in general is hard to land on a lucario that knows the MU. If he's shield sitting he has the wrong idea for the most part.
Steam is right, a grounded lucario is a better lucario for the MU.
Valdens taught me a lot about this MU when he played, It's fairly even imo.
A2Z, I beg to differ on G&W's jab being better than Luc's aside from maybe speed. I also think one should take into consideration how infrequent Lucario ends up recovering in a bad spot, Lucario's ability to Momentum cancel well and be extremely floaty (lol practically one of the few good things about that trait) allows him to stay up high almost all the time against chars not named MK and Marth, and he has all the tools snake has for mixing up when being high and then some. The nice thing about Lucario's recovery is that Lucario can still use his second jump with careful management to help get across and onstage, unlike snake who has to use it every time to recover high. Lucario also has b-reversals like snake, capable aerials (not amazing, but quick and decent range so that the opponent has to think more about them instead of just waiting for the AD like you often do against snake), and Lucario has dair stall to give him a little more leeway and mixup power while high, which works great for waiting for the opponent to either rush the luc for edgeguarding, or to wait until the opponent doesn't have as many options when playing the defensive edgeguard type. Snake's height from recovery is good but it often gets invalidated by smart opponents that frame trap well at top play, because what usually matters is when he needs to return to the ground. The only thing that lucario doesn't have that snake does to help is FF airdodge.
I hope that makes sense lol