How do you stop a deck from looking cluttered when there's genuinely a lot to show?

This is the part I never feel like I solve properly. Sometimes the content really is dense. It's not that someone over-wrote the slides, it's that the topic has ten moving parts and the audience needs to see them.

The usual advice is "less is more, cut it down." Fine, but I can't cut a financial model down to three words, and splitting one busy slide into six sometimes makes it worse because now people lose the thread across slides.

So I'm curious how people handle the genuinely-a-lot situation. Do you build one dense reference slide and then talk to zoomed-in pieces of it? Lean on build animations so things appear one at a time? Use a summary slide up front and put the detail in an appendix?

I've tried all three and I'm never sure which the audience actually prefers. When your deck has to carry a lot and still not feel like a spreadsheet, what's worked for you?