Credit@ mikeytman from reddit

" IDK if this is a left over from where some perks where removed or what but I went in a creative world. Used the “giveselfxp” command and put 999999999 which got me to level 300 (assuming that’s the max level) and I had 303 skill points (every new character get 3 points at level 0 so 303 at max level) and I was able to fully max out every skill on every skill tree and get every perk from every perk tree from every skill, fully maxing out my character and still have 16 points left over!

TL;DR At max level 300 you can fully max out your skills and perks with 16 points left over. "