Panasonic got out of the electret microphone capsule business several years ago. But certainly there are many vendors of similar commodity electret capsules out of the usual places. The Panasonic WM-6x series was legendary for a couple of reasons: They were dirt-cheap, and they had pretty flat frequency response.
But they were not noted for having very good dynamic range and they were not particularly quiet. The dynamic range could be improved somewhat using the "Linkwitz Mod". But there was no solution for the self-noise problem other than buying 100 of them and selecting the quieter samples.
I can only think that "Nature recordists seem to love [them]" because they were cheap (disposable) and reasonably accurate. I wouldn't think they would be all that useful for recording low-level sounds (like ambient background, etc.)
Nothing particularly against using them for recording voice. Certainly they need protection from plosives (like a pop/blast filter). But extremes in level (like whispering or shouting) would not be something it could handle well.
All electret capsules require power often called "plug-in power" which is a few volts. Phantom Power is a VERY different (and completely incompatible) method of powering microphones. Using an electret capsule as a voice mic rather than for a binaural pair makes no difference to powering requirements.
Connecting an electret capsule to most 3.5mm microphone inputs couldn't be simpler. But connecting one to a higher-end XLR type mic input is a rather different matter. Certainly there are ways to do it, but you have departed the concept of "cheap and simple".