Honestly, I think too many took a defeatist attitude of 'they're going to rig it anyway, so why bother?', so you had a double edged sword of both D and R turnout being depressed. On a larger scale, Elder and any other viable GOP candidate's base in Red California has atrophied into terminal irrelevance over the last 25 years; the endgame of the urban domination of rural areas. High Republican turnout and a stronger CAGOP ground game would not have mattered except to narrow the gap somewhat; anything that got out more CA Republicans to vote would've gotten out even more Democrats. The only shot Newsom had at being recalled was to make the election solely about him and leave the candidate field full of literal whos, which is probably why the CAGOP was so reticent to actually back a candidate. Elder was the strongest GOP candidate possible, but his very existence paradoxically doomed the election once he became the clear challenger to Newsom. The Democrats were not going to give up Newsom and back their own challenger, so anyone that rose to the top was going to be successfully framed as a Trump proxy, and this state swung massively against him in November. Until there is another major political realignment in America, California will be blue to the bitter end of the current party system.