Are we less safe now that Arecibo is no more?
The linked article is copied from a university press release.
Arecibo's article is more matter-of-fact but naturally also emphasizes the value of their own work.
NASA Goldstone can do planetary radar and remains operational.
As this page says:

Arecibo has twice the range and can see three times the volume of Goldstone,
while Goldstone, whose greater steerability provides twice the sky coverage and much longer tracking times, serves a complementary role.

FAST has no transmitter but presumably could take part in bistatic radar observations as GBT does.
Radar can measure distance and radial velocity ($r$, $\dot{r}$) in a single observation, especially useful when combined with astrometry ($\alpha$, $\delta$) since the two different kinds of data are orthogonal.
Given enough observations over a long enough time, astronomers can determine asteroid orbits rather precisely through optical astrometry alone.