Been weak the last couple of years. But not the last decade. Go back to 2015-ish and you had periods in the same season where USC, Utah, ASU, and sometimes UCLA or Arizona were ranked. I’m not sure I care to enough to find them for you but there were articles from ESPN writers in that timeframe arguing that the P12 South had arguably the deepest division top to bottom (might have been Kyle Bonagura but could have been the other guy he covered west coast college football with, I don’t remember).
There’s a lot of recency bias from the last couple of years when people here talk about the P12 as the fifth and weakest conference.