Time series econometrics is indispensable. Time series econometrics *research* has not been relevant for a few years now, for the lack of breakthroughs that might significantly impact practice. Although this might have something to do with the regression (no pun intended) towards simpler methods in applied work in general, and a general lack of enthusiasm of practitioners to adopt the most appropriate methods for their data. This is mostly FUD - - oh, nonlinear methods are less robust, bla bla, perpetrated by anti-intellectuals like Angrist.
That said, time series or no time series, I would agree that UCSD would not qualify as top 10 any more, since Hal White passed, and they lost Guggenberger, Santos & Komunjer in the span of a few years. 2009, when Clive Granger and Hal White were both alive would be the last time UCSD could have been classed as the top department in the country for econometrics.
Time series is very much needed and used for macro variables such as GDP, inflation, unemployment, etc.
The fenance douches relay on time series modelling, so the work is still very relevant.