dddd

Many posts to "REPLY" to, but yeah, the car enthusiasts very often prefer manual transmission and clutch, and have their good reasons.

Broken cables; I've never in 40+ years of using DT shifters had a cable break. I've replaced the cabling for other reasons, but never had the cable break.

I must confess, I'm one of the "N+1" riders that Ironfish653 refers to, and yet I do actually enjoy doing hammerfest rides on my current (though bought used) Argon18 with Dura-Ace 9100!

I didn't read through all five(?) pages of this topic, I did notice though that the OP's suggestion about new bikes coming with DT shifters seemed to have been shot down early. But then I had experiences to share about why I came back to riding with DT friction levers, and about how I thought that I achieved an efficient setup.

mstateglfr asked about the benefits of DT levers, and I recall (1) mentioning that they really seem to minimize downtime from cable and other issues (such as STI levers that suddenly "catch a cold" when the weather changes, and stop reacting to lever inputs).
And there is (2) an element of ergonomics that doesn't always make integrated levers the best, what with the wrist action that is needed when honking out of the saddle, and such as having to position one's hands forward on the bars to shift.
Setting up today's bikes with internal cabling and short, stiff cable housings going from the handlebar to the frame (3) is way more work than setting up an old bike that requires less maintenance, by far, and requires more skill and patience to perform such setup and maintenance.
Crashing a bike with integrated shifters (4) can have implications that DT levers are immune to, not to mention that integrated shifters are also heavier and more expensive.

Some folks might never feel safe while having to shift with one hand off of the bars, but I've had moments when using STI levers left me vulnerable to loss of control as I shifted during the varying conditions that often occur, just as I have had moments when I chose not to shift because I feared taking a hand off of the bars to move a DT lever.
I think that riders are capable of deciding how safely to use their particular setup regardless of what setup that they choose, and can understand how shifting from the handlebar can offer certain advantages, including better racing performance in certain circumstances. I've never liked shifting DT levers using "corncob"-style freewheels or cassettes, this having mostly to do with the hilly terrain where I rode.

The best argument for using DT levers might be that a lot of now-inexpensive older bikes have them, and that they can work pretty well. And for urban riders who don't want to park their bike leaving too much in the way of merchandise value out of eyeshot, it's good way to go since their bikes don't have to be as attractive to roaming thieves.

If I'm biased here it is in the sense that I have quite a few bikes, am familiar with all of them, and don't ride the same style of bike on all of the training and recreational rides that I participate in weekly. I can't be convinced that any of the popular shifting systems offered over the past 50 years is deficient, except in the sense of (A) serious competition where the rider is giving it his or her all (and needs a more-current bike), or perhaps where (B) a modern bike is poorly maintained or where (C) a vintage bike is assembled with poor drivetrain component choices.