Why is Vertical Aerospace ($EVTL) crashed while Archer ($ACHR) and Joby ($JOBY) are worth billions?

I'm following the eVTOL space and the performance gap is confusing. Archer (market cap \~$6.8B) and Joby (market cap \~$15.2B) are being valued as serious players. Meanwhile, Vertical Aerospace (market cap \~$550M) has completely crashed, despite all three having a similar business outlook.

What is the market seeing that I'm not? Is there a fatal flaw in EVTL's tech, funding, or certification path that justifies this massive difference in valuation?