I disagree on your interpretation of relatively high. Weekly RSI is about 45 and falling. Historically the only time we get under 45 Weekly RSI is during the significant bottoming events in January 2015 and December 2018. I would say 45 Weekly RSI is relatively low.
To get much further down you have to assume a capitulation event. We already had our capitulation this cycle. Am not convinced we need a second one this cycle. During the 2013 first crash we never got below 48 Weekly RSI.

I see where you are coming from. The only thing I would add is we fell from 6k to 3k from these weekly RSI numbers. I don't discount a bounce here. I also would not be surprised if we go down to 7k. Beyond that I don't expect much further downside. I have been doing some buying at these levels , so that says something of my expectations.