According to his tweet [1], there is a separate hiring track for front end engineers that does not include that much algorithmic knowledge. I was surprised too.
[1] https://twitter.com/dan_abramov/status/1078658656344903683?s...
[1] https://twitter.com/dan_abramov/status/1078658656344903683?s...
For even moderately sized companies, someone with wider knowledge will fare better, because such companies aren't going to spend $500k/yr on someone who doesn't know algorithms (or on someone who ONLY knows algorithms). The marginal cost to Facebook is near zero, the marginal cost to a smaller company certainly is not.