The information broadcast by transponder is significantly more precise than what you will get with radar, microphone array, or binoculars.

GPS Lat & Long Barometric Altitude Ground speed & track angle Rate of climb/descent

All updated every second or so.

I can just about guarantee it has nothing to do with targeting and a lot to do with making Venezuela unsure when strikes are about to start, both for security of the forces launching the eventual strikes (if any) and to harass/wear-down Venezuelan air defenses by keeping them very alert.

If our aircaft were flying transponders-on during all these exercises then suddenly went dark, it’d signal imminent attack. This keeps them guessing. Possibly we’re even playing around with having them on some of the time for some aircraft, and off at other times.

We don’t do that with AWACS and such near Russia because we’re not posturing that we may attack them any day now, and want to avoid both accidental and “accidental” encounters with Russian weapons by making them very visible. In this case, an accidental engagement by Venezuelan forces probably isn’t something US leadership would be sad about.

> is significantly more precise than what you will get with radar

Is that increase in precision much larger than the plane itself? If it's not then it couldn't possibly matter in this application.

Further radar is not a static image. The radar is constantly sweeping the sky, taking multiple measurements, and in some cases using filtering to avoid noise and jitter.

> GPS Lat & Long Barometric Altitude Ground speed & track angle Rate of climb/descent

You get or synthesize every one of those with radar as well.

Even good stereopair like a WWI navy guns rangefinder, will give you all that info, of course not precise enough to lock a missile - well, transponder also wouldn't let you to anyway, and thus all that transponder precision is pointless in that context.