There’s a whole lot of information posted above that doesn’t fit my experience. I have STI shifters on my commuter bike that have over 25,000 miles on them without a single problem. The STI shifters on my touring bike have 10,000 miles on them without issues. I’ve never broken a cable in the shifter. The broken cable issue is more a problem with newer shifters starting with the 10 speed 105. I don’t carry spare cables nor other spare parts. In 10,000 miles of touring, it has never been a problem.
I’ve never had problems setting up the front derailer due to the shifters. The derailers can be a problem but it’s not due to the shifter.
Brifters are robust and good equipment. I’ve crashed directly on one of them and never had a problem...and that was 10 years or more ago. They are still in use.
Finally, I also see a lot of old shifters at my co-op. Many of them just need a shot of WD40...yes, that stuff...and they are back to working just fine.