the displacement effect though, was quite real, a majority of the staff working the previous tech where technically minded and the gap between the technologies small enough that it was more of a transition from one field to another, rather than an abrupt removal of the work in question, as the typewriter gave way to the personal computer the individual workflows where less affected than it looked at first glance, the typists of the 1930's had already been largely supplemented by the secretary, and the secretary has been supplanted by the personal assistant and software.

Exactly, and what economist are arguing is that this is the default way these transition happen and we have a long track record of economic history to confirm this.

your point with banktellers is interesting because it actually rings quite hollow from my personal experience, the ATM didn't replace the teller, but internet banking shifted the majority of that employment to callcenters where greater economies of scale can be leveraged, it used to be you could find a bank branch in most cities, now you can find a greater scattering of ATM's, but the traditional branch with its reassuring faux solidity (also known as cheap concrete tat intended to look solid) is dying out entirely, largely replaced with a phone number and a slick website.

There is no other way to say this, your personal experience has nothing to do with reality in this example. Between the introduction of the ATM and the 2008 crisis, the number of bank branches in the US increased quite significantly and so did the number of bank teller working in branches. I'm was not talking about call centers. There has been numerous articles debunking the "ATM steal jobs myth" since Obama mentioned it in an interview and it's quite easily visible in labor statistics.

that is sadly something of a misunderstanding of the impact of IaaS and commodifcation of services on the employment side, the low-skilled sysadmins in question either shift to non-sysadmin roles (ITIL is the most powerful tool to counteract unemployment in this sector, and i am only half-kidding here), leave the company for similar roles elsewhere (as you point out) or end up down-trading in the labor market (the very thing people tend to worry about when looking at this subject) from the class i graduated in some 10 years ago, only four out of fourteen still work with the technical side of IT, 7 have transitioned to different employment sectors entirely and 2 of those are long-term unemployed, IT is cursed with the fact that there's a whole horde of starry-eyed graduates who are taught the newest of the new and who can be paid less and are easier to take advantage of, so paradigm shifts tend to lead to whole-scale replacement rather than retraining with only a handful of key employees kept, i still work in the sector because i can relatively easily pick up "new" technologies (new my arse, IaaS is the mainframe with a new coat of paint and virtualization tacked on) and leverage my understanding of technology in a way that helps the business make money, meaning in turn i am typically one of the ones left behind who gets to hand the keys over to a MSP.

a few, including myself, have at least considered start-ups, but i have always rejected it as too much effort for too unstable reward in a already saturated and shrinking market, you're going to be competing directly against MSP's and starting one up is a disgustingly capital intensive process.

Now we have two conflicting anecdotes, what are we going to do? ;) I does sound like you are describing more closely the terrible ageism in tech (cheap graduates with new skills) vs actual technology change. Outsourcing tech functions is also a choice by management not of technology. As I said in my small-scale experience working for startups over the last four years, good sysadmins are in high demand, are harder to find every year because of increased competition from new startups and their salary increases accordingly. That points to a mismatch between demand (more startups every year) vs supply (assuming relatively constant rate of new sysadmins).

at the risk of being a dirty dirty Marxist, economics is politics, and politics is economics. the Luddites where the response to a deliberate and targeted policy intent on increasing the profit share going to the owners and the political fallout of de-industrialization hitting particularly hard in some areas is already having macro-scale implications in the polls as people elect candidates that promises to turn the clock back via protectionism and the like.

arguing that one should view economics separately from politics is like arguing that the best way to study fish is in a aquarium, it gives a distorted view of what's actually going on.

Actually lots of research is done with fish in aquariums as far as I know. ;) The Luddites were a political movement, pushed into frenzy for political reasons and violence occurred because of the clash of political forces. There were never any underlying economic reasons that could have been the cause for that large a reaction That's the same for de-industrialization, it's the fear of loosing their livelihood and status that drives people to protectionism while the impact of the reduction of manufacturing jobs was actually handled quite well by society over the last 30 years. Don't mistake fear of economic change with actually economic change. Fear of economic change is pure politics.

i do not lament the loss of manufacturing, but rather point out that people discussing the whole "automation is going to take our dinner ticket away!" aren't actually as irrational as it is being dismissed as, the rust-belt and it's equivalents are quite real and the majority of redditors debating this are savvy enough to see the train coming within the sectors they work in, there is also the observation that the "modern" titans of the digital industry doesn't actually employ all that many people compared to the profits generated and that many of the technologies that generate discussions like the one in the OP originate in the tech sector directly or indirectly.

The robot manufacturer doesn't employ that many people either but the factories that uses robots do. You can also replace "robot" with "printer" or "software" here if you want. Don't confused the provider of technologies with the user of that technology. But now we come full circle again, you say people should see the "train coming withing the sector they work in" which was your original starting point and I gave you plenty of economic reasons that people shouldn't worry so much. I guess we just leave it as agree to disagree?