I recall a discussion about the upcoming Empyrean aka Railjack last Tennocon, about making "islands" and Railjack was instead going to reconnect those islands. Kuva Liches, so far, are the exact opposite. The Kuva Lich content is creating a dull, uninteresting island: the only way for one player to even detect another has a Kuva Lich is by going on Kuva Lich missions, or in other words, going to Kuva Lich Island.
Kuva Lich island doesn't have anything interesting. The entire system just feels padded, bloated, pointlessly frustrating to the player. Getting Murmurs is a tiring slog that just drags on and on. For a brief moment, when we got murmurs for squadmates liches, that was much better, I'd almost say about right. It also meant that if someone found their lich out the gate and killed it, well you weren't getting any more thralls, but you got a bunch of murmurs so everyone's happy. Now? If someone gets and kills their lich out the gate, everyone else feels like they should be doing these missions solo, further isolating the experience on Kuva Lich Island. Kuva Lich Island doesn't offer any side benefits, anything otherwise interesting that could be done on the island while you're trudging your way through your murmur farming.
You talked about a "Power Inversion"... this doesn't feel anything like that. The "oh, screw it up and the Lich just kills you" mechanic just feels pointlessly punishing the player for having the gall to actually play the game. The RNG on top of RNG on top of RNG feels padded, an attempt to conceal a lack of actual content by needlessly frustrating the player. Kuva Liches don't feel actually difficult, just cheaty and BS and makes my eyes roll. I don't feel a sense of accomplishment when I finish a lich. I feel a sense of "ugh, done. Why do I want to do this?"
Meanwhile, the Liches themselves... me, personally, I find the "Logical" personality to be akin to nails on a chalkboard. The "Jovial" personalities I find more amusingly irritating. That said, I know at least one friend who has the exact opposite opinions in the Lich personalities but all of this wouldn't be such a drawback if the Murmur hunt wasn't so long and boring and aggravating. The Kuva weaponry having the Paracesis' rank 40 with 5 forma mechanic is a worrying sign that makes me want to look elsewhere going forward because it is yet another long, boring, slog. A way to pad out by demanding the player rank up the same weapon 5 times, demanding 5 times or more the time investment for the same amount of content.
Kuva Liches has made me consider trying Destiny because if this is the way Warframe intends to go forward... perhaps it's time to find some other game that still respects its players.