We love doing 5 Disney days best structured with 4 full days (with Rope Drop & lengthy midday breaks to then close out the park, maybe one late start if we need it on day 3) and then one 1/2-3/4 departure day. In the past, the difference between 4 & 5 days day has been only $10 more & well worth it for that extra morning/afternoon to do your favorites another time & shop your way out the parks (which is what we usually do). It may be more than $10 difference between 4-5 days, but I’d say up to $30 is still well worth it
For 1 just day of Hollywood, I agree it’s not worth to split stay, but if you have more than 1 day’s worth of Hollywood/LA it’s totally worth it to get a room in the vicinity to avoid having to do that traffic twice! On most our trips we make at least 1 stop in Hollywood for a Disney pin event of some sort so we do that drive once a trip &
that is more than enough for me.