PG13 was available, and Portland was bidding, reportedly offering all three of those 1st round draft picks. BUT, the same reports noted that Olshey was holding CJ untouchable in those trade talks meaning he had to be offering something like Harkless, Meyers, and the 15th, 20th, & 26th picks in the same draft. Or maybe he was holding one of those picks and adding a future pick. Olshey even said something along the lines of "why would I trade CJ for PG13; I want CJ to play with PG13"
that's how loopy Olshey is about CJ. Now, it's entirely possible that Indiana would have still wanted Oladipo and Sabonis over CJ and three draft picks. It's worth noting though that at the time of the trade, Oladipo was coming off his worst year as a pro while CJ was coming off his best. And we don't know if the same Olshey-loves-CJ bullshit was going on when Jimmy Butler and Kawhi were available. Maybe, maybe not
all that aside, your seeming insistence that Portland has to trade CJ for a player just as good, or better, makes little sense to me. Most trades don't work that way, and very few trades don't involve risk...except for the ones Olshey likes when he's dumpster shopping, obviously. Portland has driven the car into a dead end with the Dame/CJ backcourt; they need to back out but CJ, and his contract, are blocking the rear-view mirror. Remove that obstacle, back up to the main street, and pick another route. Like I said earlier, sometimes you just have to take a couple of steps back to find a better way forward