@ruby yeah why not https://www.raspberrypi.com/products/m2-hat-plus/
@ruby since the Pi 4 they can boot off of attached storage (USB3 is fast enough to see benefits). Honestly microSDs are so cheap, ubiquitous and accessible that they won't be going away anytime soon, and if you buy decent ones they last a long time (they make "industrial" microSDs for maximum endurance!). That said all storage wears out and my "home server" Pi 4 has been happily running Home Assistant on a high-quality microSD.