Is there a way to split touch bar to have both function keys and touch bar utilities I love the way I can adjust volume, brightness and locking macOS with the touch bar. However, the fact that the left half of the touch bar is always empty is terrible. There's an Esc key on the left, enormous amount of blank black space and then utility icons like brightness.

Is there a way to put at least F1, F2, F3, F4 on the left half of the touch bar without removing the utility buttons?
BetterTouchTool can do this. You can add your own buttons to the Touch Bar, placing what you wish instead of the app controls area on the bar. To retain the control strip alongside BTT, select the app to customise on the left, then App Specific → Touch Bar Behaviour → ‘Show Better Touch Tool Touch Bar, show system control strip’.

Keep in mind the left half isn't always empty unless you're only using apps which don't provide app controls on the Touch Bar. Using Better Touch Tool for a certain app hides the app controls area.