This is the first offseason that both Carmelo and Lebron have been free agents in. They've had options and extensions before that kept them from hitting the open market at the same time. They didn't hit the market at the same time but they were both still free agents for a period of time this offseason. At Lebron's age he could still get a max deal from any team that he wanted to sign with. Meanwhile Melo was basically paid to stay away from a playoff team in OKC and a lottery team in Atlanta. He ended up needing to settle for a league minimum deal with the Rockets for 1 year. Even at the league minimum, I don't think he could have picked any team in the league to go to either.
I remember during their rookie seasons there was a debate about which them deserved Rookie of the Year more. Carmelo took the Nuggets to the playoffs that year and Lebron missed out on the Cavaliers. Statistically they were fairly similar that year also. Lebron didn't have a year in college like Melo did but they were closer in talent throughout their first 2 or 3 years in the league before they started realizing their potential a bit more. Lebron was always more of a playmaker and it took a little while for Cleveland to add players around him so he could show that as well. He had to do a lot more in his first and second year in the league. His longevity is definitely uncommon, he's 34 and still worth a max deal, but it's odd to think how far Carmelo has fallen just in comparison to Lebron because they were compared so often early on. I don't think Melo could have gotten a max deal from any team he wanted just 2 or 3 seasons ago but Lebron has never been in a position where he couldn't choose his own destination and that other team would say no to it.