Turns out despite Lucas' down smash now working like a Tatsu, it still has utility.
I wonder what other "nerfed" moves have utility?
"Tatsu"? What do you mean? Do you mean like how Tatsumaki's not really useful outside of certain situations, but in specific situations, it excels?
It's a myth really that lesser knockback makes a move better at comboing. Lesser knockback means lesser hitstun, so while it lets you combo with an attack further, you also can't combo with it as early as you could before. It's the exact same for comboing, the range where it does just got switched forward a little. A move becoming better for comboing due to damage nerfs is only true if it works from 0%, and Falcon's uair doesn't start linking until around 20%+.
I have to clarify though that low BKB, low KBG and low endlag are what matters for comboing. In the case of damage nerfs I believe it's only BKB which decreases, so it only switches the range this way.
Biggest example of this would be Falco's Bair and his Ftilt. Bair has no base, but amazing growth. This leads to the ability to combo from and to it at low percents. Hell, you can even chain them together at low percents, but at high percents, it just kills. Main reason is that it does a ton of damage to offset having no base knockback.
Inversely, Falco's Ftilt also has no base, but has a normal growth of 100. You'd think that it'd be great for low percent chain-poking, but you're wrong. Even though it does 9%, most characters can tank the hit like it was his jab. I don't even know why since other poke kicks have some base like Luigi's has 2, (Dr.) Mario has 8, and Captain Falcon, Fox, and ZSS have 10. Ryu? He has 66, but that's because his light Ftilt only has 46 growth kind of like how DK's Bair has a ton of base, but little growth letting him chain Bairs like no tomorrow, but in Ryu's case, he has a fast, safe, and strong poke to knock you back unlike the others which cause enough hit stun and knockback to push you out a little and give them time to move and unlike Falco's which doesn't do much until mid-percents.
Basically, as Trifroze said in his post, looking at numbers in black and white doesn't do much. You have to look at everything which is all the other numbers. I mean, could you say Sheik's Ftilt is a good kill move because it happens to have 158 or 165 growth? No, since it only does 4%. Granted, you could say because of the growth, the 20 base, its speed, etc. is what allows it to be such a good combo tool.