I think if Cyberpunk 2077 is to have a boss, he should move slowly, and have large, predictable, and easily-dodged attack patterns. In addition to the fantastic "glowing eye" idea
@kofeiiniturpa came up with, of course.
You should have to destroy this eye, or some other weakpoint, three times in a row before the boss is truly "dead," but then he should reform in bigger, more "badass" fashion, so that you can repeat the process but with new attack patterns and a new look. For example, he dies and then turns into an ascended mechanobear with lightning talons and lava fangs. He can also spit acid and fart rainbows.
Of course, this might be too easy for some players. The best way to improve the difficulty is to give the boss more health. At normal, he has, say, 1,000,000 health. At Hard, he has 15,000,000. At Very Hard, he has 60,000,000, and then at Ultra Insanely Hard Holy Sh** I Can't Believe I'm Doing This, he could have 150,000,000 health.
The players damage and health will need to be nerfed too, of course. If it were left the same they might feel overpowered, like they aren't really progressing in the game. Once the boss is finally defeated, once and for all, the credits should roll and the game should end, so the players know they truly accomplished something major.
Yeah, on a serious note, this is one of those false tropes about the genre that bother me. Even Sard is guilty of bringing it up quite frequently.
"Because its Cyberpunk" is a bad reason to punish the player. You MUST let them win every now and then. And that victory should not always come at some massive cost.
You can tell a gritty, dark, and punishing story without resorting to the same storytelling tropes over and over and over again.
I think the Witcher handled it fine from a story perspective. Sometimes your decisions had very little downsides, other times they had massive ones. Sometimes there were
only benefits to helping someone.
Variety is the spice of life. I don't care if you're in a Cyberpunk world or not.