Question Regarding Network Upgrades + BTC/BCH

So BCH was basically created when Bitcoin developers couldn’t reach a consensus on whether to expand block size or not. I personally don’t think Bitcoin is viable at this block size going into the future (fees were close to $100 when demand was peaking in April/May and that was only a fraction of the demand that is possible moving forward)

What happens in the future if Bitcoin developers agree block size needs to be increased? Will Bitcoin then essentially be Bitcoin cash and render Bitcoin cash without a true use case since Bitcoin will have the name and same features? Or is it not possible to increase block size now? Can someone explain this to me like I’m 10?