Coaching any local team differ in many aspects from coaching a national team . With a local team, the coach has the opportunity to work with players he knows well, has good communication with and understands each player's abilities as well. While when training a national team, the coach needs to deal with players from different clubs (So from different cultures as well), and must work to encourage the national spirit by integrate players to achieve the best possible performance. A national team coach has additional pressure from the fans and the media, while the coaching pressure in local teams is relatively less.
Ultimately, and either for Ancelotti or any other coach, coaching a national team requires strong motivational and leadership skills as well as a deep knowledge of the game and playing strategies. It's not an easy task by all means.
It is not purely like that. Training a national team may on the one hand be a burden, but frankly, they earn a load of money and know that the pressure only comes sporadically during the month, or even the year. It is not that dramatic
It is assumed that the large financial returns equal the level of pressure that the coach will be exposed to, and if Ancelotti was only thinking about the money he would receive, he certainly would not have renewed his contract with Real Madrid and missed this opportunity. I do not think that it is easy to manage a team with the strength of Brazil, especially in a global event where Brazil is accustomed to winning titles, and therefore the task of maintaining this position is very difficult.
The same level of pressure also varies among players, and if you ask them, I assure you that they will admit that they are exposed to great pressure in the matches in which they participate with their teams, compared to the matches with their clubs. In addition, the players play in different clubs and it is not easy to coordinate between them during a short training period. Can't imagine the great responsibility that the entire training team will assume.