I guess I would say that subcontractors are more like hourly workers (who are time tracked meticulously in almost all industries) - not salaried like software engineers, who would deserve the respect and absence of tracking.
Also, Unions hate this right?
For example, they can look back through yesterdays events to see that their plumber showed up - and then they'll know they need to go check on the work. The alternative is trying to get the plumber on the phone to figure out if the work had been completed or not - which is difficult in 2023.
There's not a lot of unioned workers in most states for residential construction. But autoworkers, and anything else in manufacturing would be used to the constant monitoring. Commercial construction also typically has fulltime site superintendents, who would do this anyway.
The GC can often bill it down to the homeowner as antitheft, which reduces time/money to complete the build. The biggest being time. An example, if custom windows are stolen, it could delay a project by months right now.