Why do you say they're "absurdly" under-capitalized? They already make laptops. The phone's hardware seems fairly standard, no risky R&D gambles, and the software is Linux/OSS...

They re-badge laptops that someone else makes. It's not like they have their own factory in China. In this case they are not re-badging, they are building their own phone and phones are considerably harder to make. There are QA processes that require machines that cost >$1M. It puts them into a situation where they have to trust their manufacturer 100% and pray. Essential spent ~$100M making their phone and they had help from Foxconn and awesome industry connections. $2M isn't gonna cut it.

It is impossible to run Intel or AMD laptop without using their firmware blobs. Check Libreboot FAQ.

Only free thing at the moment is ARM, like Marvell CPUs.