Impossible to find? You don’t have salary info on that listing and a quick google shows that your salaries are something like half what I’m making as a remote RN engineer. Very unlikely that it’s because of RN.
I make around $200k + equity as a Staff Engineer, fully remote, though as my company is also private, equity === 0. I would say I am moderately underpaid in the current market but I'm happy with that tradeoff since my company is fully remote, great work life balance, and I work with great people.