Here's your fundamental problem:

Tech workers have thought of themselves as the geniuses, the exceptions, not as part of the general labor pool. And they have been! They have received very high salaries, good benefits, sometimes stock options. There have been a lot of tech workers who have become millionaires - not 50%, but enough that it felt like they had a realistic chance to do so.

It's really hard to persuade people like that that they need a union. Unions are for people who can't take care of themselves, who need a union to protect them from big evil management. Tech workers don't see themselves that way.

Also, unions often have bureaucracy of their own. Tech people generally hate bureaucracy. Having the company's version is bad enough; adding a second one on top is a really hard sell.

So you have a really big headwind for trying to persuade your target members that they should want such a thing.

But you have an opening now, with AI and concerns for jobs. People may be more open to the idea than they historically have been. The problem is, the people that you need to get, the ones who are deciding to implement AI, are typically the ones who still think they're the special ones, the ones who will always have jobs, so they still won't see the need, not for themselves. You have an opening with some people, but I'm not sure it's enough for you to be able to make real change.