Why the Pelicans do this trade: This is not a ton of overall value for the Pels, but they get a solid shooting big man to put next to Zion and increase their guard rotation. They also fall below the tax.
Why the Raptors do this trade: This is a very low price for an All-Star caliber player. Brandon Ingram fits the Toronto mold of being a long, switchable defender and he boosts the offense and shooting. Also, BI fits their timeline. With this trade, the Raptors starting lineup of Quickley, Barrett, Barnes, Ingram, Poeltl would all be 23-28 years old, all near the beginning of their prime years.
I wouldn't expect this trade to happen until around the trade deadline as I expect the Raptors aren't trying to win much this season and want to get another high draft pick to add to this core group, but BI isn't likely to drastically change their fate for this year.