It is plausible that our visible light signature might be reduced (though I don't agree it is necessarily wasteful - like lighting up evening outdoor events). But we should consider the entire RF spectrum. You'd have to go to an extreme to not have a modern civilization without notable RF emissions at some level. (e.g. Dyson sphere).
Section 2 of this paper has some fun info on the ability to detect our radio signature at great distances.
For example, the Arecibo Planetary Radar typically transmits at a power of 0.8 MW and a frequency of 2380 MHz, with a gain of ~108. This means that low bandwidth transmissions from Arecibo, with B ~ 0.1 Hz, would be detectable by a watcher with a 1 km2 receiving antenna at distances up to 200,000 light years, while high bandwidth signals, with B ~107 Hz, would be detectable out to about 5 light years by the same watcher.
By comparison, television carrier waves have similar power but gain ~10, B ~ 1 Hz, and frequencies in the range of 100 to 2700 MHz; such signals could be detected with a square kilometer array out to a distance of about 50 light years.
Section 2 of this paper has some fun info on the ability to detect our radio signature at great distances.
https://arxiv.org/pdf/1207.5540.pdf
For example, the Arecibo Planetary Radar typically transmits at a power of 0.8 MW and a frequency of 2380 MHz, with a gain of ~108. This means that low bandwidth transmissions from Arecibo, with B ~ 0.1 Hz, would be detectable by a watcher with a 1 km2 receiving antenna at distances up to 200,000 light years, while high bandwidth signals, with B ~107 Hz, would be detectable out to about 5 light years by the same watcher.
By comparison, television carrier waves have similar power but gain ~10, B ~ 1 Hz, and frequencies in the range of 100 to 2700 MHz; such signals could be detected with a square kilometer array out to a distance of about 50 light years.
RIP Arecibo