@middling I’m echoing what the others have said. My admittedly anecdotal evidence is my twins, who got very different acceptance offers from the same well-respected school. The one with higher stats, spectacular ECs, etc applied ED and got less merit $ than her sister who applied RD.
She was 100% certain about the school and we knew it was in our budget because of the NPC, so ED was not an awful thing. Our priority was maximizing her acceptance chances. She’s now a rising senior and absolutely thriving there. But it stings a bit that her twin was offered more $ with lower stats.