Try adding a break in Honolulu. It is indeed a long flight from Los Angeles but I found it's bearable if you spend a few days in Honolulu. Also, Jetstar-Melbourne can be very cheap in economy or it can be a very good price/value in what it calls business which really is just premium economy in today's transcontinental flights.

Before the pandemic saved me from ever having to do it again, I was traveling from Portland to Hyderabad twice a year, and I told my manager that I wouldn't go back unless I could stop over in London for a day before continuing on to Hyderabad. Never did find out if that would have been accepted or not, but I was so tired of that particular three-flight nightmare.

Maybe Starship can turn that trip into under an hour in the future.

I'm not sure why this is getting downvoted. Point to point travel on Earth is one of the proposed uses for spacecraft.

I didn't downvote, but it seems unlikely that either of GP's endpoints will ever boast spaceports.

Melbourne is on the coast so an offshore platform will work on that endpoint. New Mexico has a spaceport already. Baring one opening up near Denver, flying to the west coast and then taking a Starship would be possible.

I'll take your word for it with respect to Melbourne, which is a lovely city I thoroughly enjoyed several decades ago. "Spaceport America" is a silly boondoggle that will never launch an orbital flight and will eventually be absorbed into White Sands missile range. Getting from anywhere in Colorado to any populated location not in Colorado takes longer than an hour. b^)