I get the process but you'd think that in this day and age airline systems would be able to simply link two PNRs (even if they are in different Reservation Systems) rather than having to manually enter data. Seems to work OK for trip apps.
There's a huge difference between trip apps built from the ground up, completely with modern technology, vs systems that use archaic frameworks setup by IATA that were initially built in the late 90s.
Granting explicit access for carrier A to access carrier B's reservations has a whole host of legal issues around privacy as well. This is something that is being tightened up particularly by Amadeus lately, because of all the FFP fraud issues going on as they had traditionally been relaxed about it.
Lets take a step back here though and look at the broader picture.., the majority of pax are just going from A to B. That's what the system was designed for, and for 99%+ of pax, it works the way it should.
Only when you get people like members of AFF testing the limits with booking broken up journeys etc. then it falls down because the system was never designed to please the < 1% of pax. The systems and policies will never be designed to please that 1% - it's not economical.
At the end of the day, the goal is to please the masses, not pander to the 1% who want to do mixed redemption / mixed commercial. Mixed redemption and commercial, or even mixed redemption/redemption in certain cases, can be done by travel agents anyway so there are ways around the problem.
Funny how 10 years ago, when it was OneWorld policy, it was so easy and I did it all the time without issue - now all too hard, bags lost all the time, despite improvements in technology etc.
In that time we also lost a lot of knowledgeable staff in the industry, and this was very much expedited by covid.
At AA as an example, virtually everyone who was LAA (legacy American, pre AA/US merger) knew how to do full manual commands in Sabre where you could do virtually anything, whereas now there's fewer and fewer staff who know how to do it.
This was the norm at most carriers... staff knew how to do all the advanced stuff.
The problem with a lot of experienced staff exiting through natural attrition and then covid, plus a load of new hires is it takes many years to build up their experience. It's not something you can learn in a few weeks in a classroom, and that knowledge isn't passed down.
Personally, I know how to use the airport systems used by Amadeus and Sabre carriers... and especially since covid, I have found I've had to help them out by telling staff where to look for a particular function when I travel. They're all new hires, every time.
Someone said in other post that the QF system has a "Find Connections" button built in that does all the hard work.
All Amadeus carriers have this function, but it only works for same carrier connections eg. QF to QF or HA to HA as this is all they are allowed to do due to privacy/legal issues.
Sabre however is way too old and built on mainframes technology to have such a function.