Because your employer in tech can afford to give you a lifestyle easily in the highest couple percentiles doesn't mean you aren't replaceable and that you won't need representation as a class of worker at some point.
I'm internationally mobile, so I'm often the newcomer.
(And from a philosophical point of view, programmers are so well paid that even taking that down a nodge to the benefit of the general public would be fine. What we have to make sure is that forming new tech companies becomes easier and easier---so that any general cheapening of programmers benefits the customers and not the owners of companies.
Traditionally, unions are the very opposite of lowering barriers to market entry.)
The problem is, taking that down a nodge will not benefit the general public. All the surplus will be eaten up by the companies.
I suppose there are two ways to view this - putting up barriers to entry vs. preventing wages from being driven down by encouraging everyone and their dog to become coders. At this point I sort of see it as both at the same time.
The reasons unions could be useful in the future is both to preserve a reasonable standard of living for tech employees and to help oppose unethical demands from employers. Right now, tech employees have some leverage over their bosses. Without unions, this will eventually end.
That can easily be fixed by plugging tax evasion loopholes and generally taxing higher.
If there's a will then there's a way, the problem is pretty much finding the way everybody agrees on.
Imho it seems like pretty valid approach considering land is one of the few resources we recognize as actually being finite, so it's a good place to start for building a "base".
On the other hand it's quite frustrating how accepting we have become of creating "wealth" out of nothing by printing paper money but if we try to do the same thing based on something actually tangible, like land, people lose their shit going "you can't just make up money", sure we can, we do it all the time.
If you can read German and like some historical musings in this direction (including about money), do read Silvio Gesell. https://userpage.fu-berlin.de/~roehrigw/gesell/nwo/nwo.pdf
That's why we need to keep working on lowering barriers to entry. (Not just in software but all industries.)
Whenever there's an industry where owning a company confers outsized excess returns, I want a hundred copycats to come in and compete away the margins. (For lots of industries one of the most straight-forward way to get that is to make entries by foreign companies easy. This way a country can benefit without necessarily having to grow a local ecosystem of startups first.)
I am happy to encourage everyone and their dogs to become coders, if they can hack it. Over the long run and average over many people, income is ultimately determined by productivity. Let's grow the pie.