Better is a close run thing, I could entertain arguments either way. Olivares was more spectacular and destructive, perhaps with a slightly higher apex it could be argued (though I'm unsure I'd agree). Ortiz was more consistent with fewer points of weakness imo against a wider range of styles. A bit more complete if you like and less vulnerable when not on key, as both could be. Ortiz was greater though imo. There aren't too many fighters in the last 60 to 70 years with a deeper CV than Ruben but Carlos is one of them and he was just as dominant in a historically deeper division with similar exploits to Olivares above his best weight. He was just as much of an undedicated hard drinking animal outside of the ring too, which is mental. He was borderline alcoholic when he won the title, but other than the slip against another atg in Laguna, twice avenged beyond doubt, his grip was iron over a tremendous swathe of fighters, though less devastating than Olivares. I feel like Laguna was a bit better and greater than either Castillo and Herrera though, and Ortiz put him in his place just as convincingly as Olivares did with Chucho. Herrera was probably better p4p than Teo Cruz as far end of reign goes, but Olivares was fair closer to his prime than Ortiz by then and loss was more brutal and decisive. Ortiz was very faded by that point, unmotivated and damaged by booze, and Teo Cruz was an excellent, much underrated fighter.
I've posted this before, but... Laguna x 2 Brown Locche Sugar Ramos x 2 Elorde x 2 Loi (twice at least) Lane x 2 Rosi Charnley Vaillant Kosaka Torres Bizzarro Busso Cisco Andrade Joey Lopes Cullen Takayama. That's a fecking bonkers list of wins that still doesn't get it's true worth in recognition imo. Sh#t, I'd be well impressed these days if a bloke beat the likes of Charnley, Rosi, Bizzarro etc. If Lomachenko had defended at 135 against just that level of fighter, the fans, media, writers and everyone involved in the sport would wank themselves delirious. Locche, Laguna, Elorde etc on top of that defies words. Man, I'll be gutted when Ortiz finally pegs it, the man is a ****ing legend.