This is always the case. Negotiate equity, but assume it’s worth zero. It’s not liquid and highly speculative. It’s a nice to have.

edit: which doesn’t mean join companies you don’t believe in! Please do. But don’t expect it to be there, don’t include it in life plans, don’t pay attention to valuations, etc.

If the owners try to say the equity is valuable, have them convert it to salary. Then it will be clear they don't believe their own words.