What has a union got to do with „give devs a seat at the table“?
By „seat at the table“ you mean a way to get what they want by force or against the will of the owners.
You don’t need a union to collect employee feedback. Smart management will do this and if they don’t then employees can jump ship to a competitor that does.
Why do you jump immediately to forcing their way, you’re talking the language of class struggle. A seat to negotiate with would be a good place to start, and it would lead to more cooperation, not necessarily conflict.
All companies collect employee feedback. Much harder to act upon it. Yes, workers can leave- but not always!- but isn’t it easier if they had a mechanism to negotiate with power, to talk it over like adults, instead of having to resort to quitting?