This is the general idea behind TPM/Secure Boot, but as you present it, it just sounds like a headache for performing system recovery, at no obvious benefit for security.
What's your threat model? In the 99.(9)% case it's a crook snatching the laptop, wiping the HD, and selling the whole thing and/or the parts. Evil maid is a real threat, but only practical (in terms of sophistication/cost vs benefit) for high-value targets, like C-levels, devs holding company secret keys, etc.
Also, ignoring what it is worth to the attacker, having to roll over all my credentials, freeze accounts, etc, etc, because my desktop was stolen would cost way more of my time than buying a new desktop (happily, the drive is encrypted).