The two-track market continues apace: companies that can achieve 2019-level productivity when most of their staff works from home can maintain 2019 valuations. A case in point: Vroom, Inc., a money-losing used car e-commerce play, filed its S-1 last week.

The Vroom model is:

1. Use a media blitz to get users to select a car on its app.

2. Allow them to customize…