I don't agree with the previous commenter that "nobody cares about sustainability" but it might be fair to consider it of limited usefulness; because screen and other components continue to evolve together I'd say this makes the device more "repairable" than "sustainable". It's not like you're going to be able to, or want to, upgrade the main board and keep the screen (which will become obsolete with continued eink advancement).
Still there's a class of user for this device who want good note taking but perhaps not one that's specifically useful ONLY for that purpose as the remarkable is.
I personally won't buy this device anyway because it's still too niche especially for the cost, but I'd personally prefer it over the rm2 even if money were no option.