They already get a lot of advantages during their life because of the position and wealth of their parents.
Is it bad to leave things for your kids? Nope, it's completelhy natural. But you can't claim that the society where that happens is a meritocracy.
Personally, I came from a family of public schoolteachers. Even though many families had many millions more than we did, I think our society, as experienced by the median and mode citizens, is far more a meritocracy than a plutocracy.
Does everyone get a full reset and the exact same starting point as everyone else, as if life were a board game? No, of course not. Would the world be better if it worked that way? It would undeniably be more "fair", but I think less desirable.
The fact that accomplishments are contributed to by material advantages supplied by parents (and more generally the network people are born and raised into and in) means that those accomplishments are less due to individual merit. The total contribution is 100%, so more of one contribution is less of the other.
Consider someone being gifted $999,999 and earning $1, then bragging about being a millionaire.
Or more realistically someone bragging about coming from an Ivy League when their parents are alumni and big donators.
Plenty of accomplishments become lesser when more context is revealed.
If you have less opportunity you must work much harder to be successful than a person who has more opportunity.
Yes. Being raised in a world where your physical needs are never even remotely considered is without question the single most important factor that leads to radically different outcomes in life.