I appreciate how you framed this and helped me see how identity can help us streamline the decisions we make in what we do.
I think identity can have a secondary effect of communicating to others those decisions we've made about what to do.
For example,
Someone: What do you do?
Me: I give speeches.
Someone: So you're a speaker?
It can be a way to bundle a bunch of actions/beliefs/etc into something that is quicker/easier to communicate to others. For example, as a speaker, I may write speeches, deliver speeches, book clients, travel to different companies, and other actions.
The challenges may come in the disagreements we have about which actions belong to which identities. For example, a speaker for some may be someone who speaks at corporations and gets paid for it. For others, it may be someone who gives motivational speeches to schools. For others, it may be someone who speaks on YouTube videos. So for each of those groups, they may hear "speaker" and associate different actions/beliefs/etc. and it can lead to conflict. I know I've seen some of this conflict when I tell someone I have created some Wordpress sites, they can immediately jump into "so you're a coder" and I can quickly think "no no, coders are people who create fullstack stuff, I'm just a tinkerer," etc etc.