I’m AS100k and DL platinum and fly WN often so kind of doing what you are thinking about. Overall DL customer service and operations are far superior to AS, but you have to do a lot of connections flying from the Bay Area. Also skypesos are basically worthless most of the time. If you are paying for premium class then UA will probably get you the most direct flights from sfo (more with their *A partners), but I really do not like flying them.

I find Alaska miles to still be useful since partner premium cabin bonuses are great, if those go away I would be highly tempted to just keep minimal status on AS (MVP gold prob) and push most of my flying over to international carriers since those are most of our long hauls.