Technically a strike is a specific action that a union can undertake to protest unfair wages or working conditions. Strikers are subject to certain legal guidelines, but also enjoy some legal protections as well.
But VFX workers have no union (so far) - so if they did the same, it would be called "not showing up for work" and they'd probably just get fired.
Now union or no, if enough people did it at once - so that there weren't enough warm bodies to hire to fill the empty seats - then maybe it would have an effect. But getting that many people to do it is no mean feat. At least a union can order all its members to stop work, to guarantee the strike will have the intended effect.
Another disadvantage that FX workers have is that - unlike actors, writers, directors, grips, virtually everyone else in the biz - FX workers don't work for the studios. When writers strike, they strike against the studio, and the studio can't get any writing done.
But it's not that way with fx. You can't stop working for a company you don't work for. So if FX workers successfully organized a strike, they'd be walking out on their employers - which are independent fx companies, not movie studios.
Nothing would have been gained if Rhythm and Hues' workforce stopped work - it would just have meant Rhythm and Hues would have gone under sooner. Depending on their deal with the studios, there'd either be damages owed, or a big insurance payout somewhere... none of which would help the workers directly. People would be out of a job, a company would probably go under, but the movie would still get made - the studio would just pull the job and send it somewhere else.
That's one of the problems with the unfocused angst among the rank and file right now - there's not even a consensus about who the bad guy is yet. The labor force got shafted by Rhythm and Hues - that's who they were working for, after all - and yet many are also mad that "Rhythm and Hues" got dissed at the Oscars.
Well, you can't be pro-management AND pro-labor at the same time - not if you want to actually get anywhere.
The Visual Effects Society - the closest thing FX has to an organization of any kind - is planning to organize an industry meeting soon, in hopes of actually figuring out some kind of coherent strategy to accomplish anything at all. But VES is mostly just in the business of giving out awards, and a lot of the rank and file seem disinterested in looking to them for any kind of leadership.
Which leaves the rank and file without any leadership at all, and thus nothing's likely to change unless a Hitler steps up to rally the downtrodden with promises of unicorns and rainbows or whatever.
As for me... I'm from the past. Go to China.