Why is Lateralus so popular?

I've been listening to TOOL for about a year now and I do love their albums especially the big three (ænima, Lateralus, and 10,000 Days) but I just don't get why people see this as their best. Parabol/a are peak for the album and Schism is a classic. Like I wouldn't say there is a single bad song on the album (besides Mantra but thats a soundbite) but I do find the other two better. My friend says it's cause I'm not spiritual enough to enjoy it fully and just left it at that. Am I just stupid?