If you ever change machine or do pair programming or whatever where you are not using your highly-tweaked config, and you are essentially a frustrated jibbering wreck and barely more competent than a 3 year old using a computer for the first time because there is only vi and not Emacs, or your "essential" key bindings are not there or your "essential" plugins are not there or horror of horrors it is vanilla bash and not zsh with your 9000 line config file.
These days I have learnt to abandon the configs, and learn to love the default life. Just open a vanilla laptop and guess what, it already has "your" config since they are all the defaults! Spend that mental energy and time on something else and get stuff done.