Pedantic nit: they aren't taking the lion's share, they are just taking a much larger share. CEO pay makes up a small fraction of total pay given to all employees so it's not "the lion's share".
If you follow Phaedrus's telling[0], introduced as "Partnership with the mighty is never trustworthy" -- all of it:
"I take the first portion because of my title, since I am addressed as king; the second portion you will assign to me, since I’m your partner; then because I am the stronger, the third will follow me; and an accident will happen to anyone who touches the fourth."
Other versions from around the world typically have the lion taking a majority of whatever is being divided, and whenever possible, everything.
--- [0] https://en.wikipedia.org/wiki/Lion%27s_share#The_Phaedrus_ve...