Is there any reason why date changes can not be handled online for simple Intra-Europe flights?

Does it work for anyone? Was it ever working?

My experience today:

• Spend 30 minutes waiting on old to reach agent to make a simple date change.
• Got agent with Indian accent who took another 20 minutes verifying that my ticket can be changed (is it that difficult?)
• Then I drove out of reception and call was disconnected.
• I was about 20 minutes away from the airport so decided to stop there (big mistake!)
• My ticket had 1st flight in business class, so I went to Business/ Senator ticketing at T1.
• There was only one agent at Business/Senator, but only one person in front of me, so I thought not bad.
• After waiting about 10 minutes, agents says she was leaving after dealing with current customer and I had to go to Y line. She was rude and did not know if anyone else was coming, told me to check with supervisor.
• Economy ticketing line had 6 working agents and about 10-15 people in line, but they were prioritizing people with same day issues who kept coming so in reality on one agent was taking non-same day customers. I estimated it would be at least 1 or 1&1/2 hour wait.
• I went to Supervisor desk next to check-in. Not to complain, but why ask for suggestions -- maybe there will be more agents coming to Business / Senator desk or maybe I could change my ticket online and was doing something wrong. The supervisor was extremely rude, did not want to talk, did not have agents available for business/senator, did not want to even look on website error, said that Swiss had a lot of problems and I was no exceptional and had to wait like all other people in Y line. And she said "I think you have time, because it was Sunday". Really?

I am surprised there are threads discussing F or C meals and experience - the airline fails to deliver very basic needs.

Why anyone would think spending more money on F or C? I had my ticket purchased some time ago and this will be probably last LX for some time until they sort out problems. Or I will buy only last minute when I am less likely to make changes.

Edit to add: Called again after getting home, 25 minutes and got a reasonable agent who was able to complete transaction while I was still on the phone (so I have email with new ticket already). Still took 20 more minutes and multiple holds to verify fare rules, charging for difference etc. Like other poster mentioned, 1970s indeed.