It's a simplistic model where workers have "less power" and employers have "more power". Both sides need each other. Workers only have less power individually because they negotiate separately. That's as true for software developers as it is for anyone else.

The "perks" I see being offered for software developers are essentially free for employers to offer at scale. When you're paying someone a 6-digit salary, "free drinks and food" at work are cute but pointless. Anything of real value, like working conditions, are never up for negotiation. I see lots of people here saying they've never been paid for being on-call (nor have I). Most people I've asked say they'd prefer, and are more productive in, a private office, but no employer in my city offers it. You can't just switch employers to fix this.

"Union overhead" is very low, for what workers get out of it. Strikes are actually quite rare. Boeing machinists are a giant union here, and they haven't been on strike in over a decade. Voting and compliance are strange things to complain about. Either they're already done today, but in different contexts (e.g., one-on-one meetings, if your manager listens to you and has the power to give you what you want), or they're not done today, and it would be a great improvement for workers if it were.

These complaints sound downright bizarre in any other context. I don't hear anyone looking at a modern democratic republic with safety regulations and saying "Well, things like voting and compliance are just more trouble than they're worth".