Slightly related to my other question (The exact mechanics of USD OIS Swaps: replacement of USD Libor by SOFR) but nonetheless, this is a separate topic:
US banks fund themselves via EFFR (Effective Federal Funds Rate), as well as the Secured Overnight Financing Rate (SOFR). There are OIS swaps on both rates, albeit the EFFR OIS swaps are much more liquid (at the moment): as per the answers to my other question.
Does anyone understand why the FED, alongside ISDA, decided to - going forward - drive a shift from EFFR OIS discounting to SOFR OIS discounting? The fact that EFFR OIS swaps tend to be much more liquid tells us that banks utilize funding via EFFR more than via SOFR. Why would the FED (and ISDA) encourage a shift in discounting towards a less liquid curve? Intuitively, I cannot really make sense of it: it would only make sense to me as a "marketing" or "political" move in an attempt to make SOFR a more prominent rate (as part of LIBOR cessation).