Love is better than Ryan Anderson overall. However, Ryan Anderson is (probably) better at being Ryan Anderson than Kevin Love is. And that's what the Cavs seem to want out of Love. Every possession that I saw in the second half last night, Love came down the court on the right side, crossed in front of the hoop without any expectation of receiving a pass, and then parked in the left corner. When the shot went up, Love came in from said corner to rebound, but generally had a poor chance of recovering said rebound given that he was 20 feet from the hoop when the shot went up. It was just a waste of ability.
Love is great at finding cutters from the high post, but he doesn't get the ball there. He can P&R, but with Tristan Thompson already on the court, the Cavs don't want Love bringing an extra defender into the paint to defend against James and Irving drives. Same is true with his more traditional post offense. He can shoot open 3's decently enough, but JR Smith is better at that, and so naturally gets such opportunities.
I'm not saying the Cavs aren't correct to employ this strategy. But if the Cavs want a tall guy to stand in the corner and hit 3s, they just need to get Ryan Anderson and set Kevin Love free.