The best indicator of performance is performance itself. This applied to competition means the meter goes way down in importance. It goes up importance racing/simulated racing more.
In training, this means the meter goes way up in importance.
Training the body and training for racing are two different things that are inextricably linked together to succeed.
You can hit range balls and never play on the golf course and do pretty well, but never succeed. You can play golf on the course all the time and give up a lot of muscle memory hitting balls working on technique. Then not succeed also.
Same with the power meter. It's a tool in training and possibly a crutch in racing. I don't recall looking at it more than a glance at the computer to see miles to go or my HR once or twice. The wheel in front of you or wheels chasing you don't care one bit what your power meter says.
Now, TT.......I'll glance a couple times initially to not go out too hard. Then it's a lot of RPE and focusing on staying aero. You're not aero if staring at a meter constantly (maybe if you've got a heads up display).
Replace the word "race" with "fondo", or "weeknight worlds", or "riding a century" and apply accordingly.
Also, meters and racing on Zwift is mandatory so that it functions. You can't race most stuff on Zpower. You need a meter and HRM for most A/B/C stuff. Especially A/B.