#2 His game suits Barcelona's style of play
Lacazette is a player who can hold on to the ball very well, can dictate the flow and tempo of the game and control the pace of the game. He never skips his defensive duties during the game and this season, he has averaged a tackle and 0.3 interceptions per game.
Lacazette's movements off the ball are often intelligent ones, which generally creates spaces for his teammates to exploit from. He averages 0.8 key passes per game, which is not bad considering he is a number 9 and not a winger or a midfielder.
Barcelona might start in a 4-3-3 formation but always revert back to 4-4-2 without the ball with Suarez usually playing in front of Messi as a sole number 9. This means that a Barca striker must know how to hold on to the ball, be willing to press high and win the ball back without getting cautioned.
Also, Barca is known for playing possession-based football and hence, needs to have a striker who can provide key passes and take part in the build-up to the goal.
If Lacazette does make a move to Catalunya he would flourish in an environment that plays to his strength.