In Apex, there are characters with abilities and they speak. I think it's because of what they're saying, also you can unlock a ton of phrases for each character.
There are micro-transactions in the game.
But mainly, as an adult gamer, I wouldn't let my kids play age inappropriate games. With this new game you are forced to play as a squad of 3, so unless your child is DEFINITELY playing with friends their age, they will be paired with and exposed to over 16's with voice conversation. Believe me there are people grooming children on gaming, and in the very least shouting abuse and terrible language.
Also, from a non sinister adult perspective, it's irritating when you play a game 16+/18+ and a child with poor internet (because the whole family are using it) and it causes a delay with how you interact with other players including enemies, a terrible headset causing feedback, echo, and other household noises in the child's audible background, so you can't hear enemy footsteps and/or you lose because the child can't grasp the idea of team play or tactics or the concept/mechanics of a game due to being too young.
Apex has become popular because it's a new Battle Royale game that was running well. As far as I remember the isn't much in the way of blood/gore.
If you're ever unsure of a game, watch some YouTube videos of the gameplay. But please, if your child is years off the age restriction, stay strong, say no.
Age restrictions are there for a reason why only adhere to them for smoking/drinking and films?