TL;DR. Bilt Blue ($0) launched in February 2026 as the no-fee anchor of Bilt 2.0 (issued by Cardless). Its flat 1x earn on most spend is not the point; the point is paying rent, earning Bilt Points, and unlocking the full Bilt transfer partner list (American, Alaska, Hyatt, United via partners, Air France/KLM Flying Blue, and more). The Sapphire Preferred ($95) is a traditional bonus-category card with 5x on Chase Travel and 3x dining. They solve different problems: Bilt unlocks rent as a points category; CSP optimizes everyday non-rent spend.
The three dimensions that actually decide it. First, rent. Bilt Blue is the only major card that lets you earn points on rent without a transaction fee (subject to Bilt's transaction-per-month requirement). CSP cannot pay rent in any practical sense. Second, earn outside of rent. CSP's 3x dining and 5x Chase Travel crushes Bilt Blue's flat 1x. Third, transfer partners. Bilt has Hyatt (huge), American (rare and valuable), and Alaska. Chase has Hyatt and United. The American transfer is a unique reason renters open Bilt.
Real customer scenario for each. If you pay $2,200 a month in rent and live in a city with Bilt-eligible apartments, Bilt Blue earns roughly 26,400 points a year on rent alone, worth $300 to $500 in airline transfers depending on partner. CSP cannot touch that. If instead you own your home or live with parents and your largest categories are dining and travel, CSP is the better single card.
The trap to avoid. Treating Bilt Blue as your only card. Outside rent, the 1x flat earn is below market. The strategy is Bilt Blue for rent plus a category card like CSP or Amex Gold for everything else. Renters who only carry Bilt are leaving 2 to 4 points per dollar on the table on dining and travel.