As for software engineers (apart from SQL ones who would of read your UNION JOIN as a whole different sentence), most grown up in a work environment that has seen the need for Unions moot as tech companies shifted in perks/remunerations that exceeded what many a Union could of dreamed of achieving. That alone seen the driver for Unions moot in many eye's, combined with a lack of tech focused Unions and the shift from lifer work mentality to few years being classed a long time at a company. Times changed and moved faster than many Unions.

However, many tech companies grown to the stage that they ain't all software engineers and the size/scale of them has seen them grow to the stage that some level of check like a Union wouldn't go amiss and opinions about unions as a whole been slowly improving in the past few years after decades of disdain. Thing is, what type of Union and is the need for a larger more tech orientated Union or lots of smaller ones? That's the crux.

Though when I started in tech, the worry about competition bugging the water cooler was the edge-case worry, today it's the company itself that has become that worry and less of an edge-case as well. So clearly the use of Unions does have some safety in voice for employee's.