>>5853000490 was not terribly slow in gen 4.
https://www.smogon.com/dex/dp/pokemon/lucario/We can all admit it isn't FAST but that isn't the same thing as being SLOW. It's a great scarfer and outspeeds important threats. In gen 4, 90 speed was absolutely usable.
>A simple spread of 252 Attack and 252 Speed EVs is perfect for Lucario, as it doesn’t have much bulk and aims to hit as hard and fast as possible. Adamant is the preferred nature, as it helps OHKO very bulky Pokemon such as Skarmory and defensive Latias with +2 Close Combat and Crunch, respectively. However, Jolly has merit to outspeed Pokemon such as offensive Suicune, most other Lucario, slower Gliscor, and Rotom-A. This is especially relevant when running Ice Punch, as Lucario now outpaces slower Gliscor and Modest Zapdos, threatening to OHKO them after a Swords Dance boost.Not being able to outspeed starmie, gengar, infernape, or flygon, as examples, isn't the death sentence you think it is. It was perfectly fine speed-wise at the time; a flaw, but not an absurd detriment. You would have known if you were there.