I voted number 5.
To give a bit of context, in a world as futuristic as the one we will find in cyberpunk 2077 having boss fights would be fairly normal, a megacorporation will not spend too much money on the normal run of the mill cannon fodder they may give them some upgrades but mostly they would give them the most basic ones, but the leader of the project or the manager or whatever you want to call it would be far better armored, 2 reasons:
Reason A: the manager, aka leader of the project, aka team leader, could be the one that is managing the money the corporation send to his group as such he will have a higher salary and more resources that he will be able to distribute however he wants, getting high quality mods for himself while the regular members get only normal mods would be fairly normal, as such once us the hero comes we could find that the "boss" actually is tougher because he expended more money on himself and got better quality mods, than the regular goons.
Reason B: the company considers the mission, project or task so important that they send an elite person of the company to oversee it, this person not only will have top of the line mods they will also have training on how to use them in the most lethal way possible, this person may end up being the controller of the manager or the bodyguard of said manager, etc etc, but this would mean that there would be a person with not only top of the line mods but also training for it. in other words a "boss", and last but not least in this kind of world with megacorps, the megacorps are the equivalent of governments so it would not be surprising for them to have armies and that you could find that battalion 5 is where some of the toughest rookies live, while battalion 9 are veterans from fights with other corps, while you have battalion 11 being rangers, battalion 12 being seals, battalion 13 hackers specialist, and have 2 special division one with super elite soldiers of all disciplines and another with some super elite type bodyguards that will protect the companies big-shots. In other words you could just in 1 corporation have enough to give you a lot of tiers of bosses and enemies, you could even have full armies of pseudo-boss like characters with a proper boss at the end of it. And remember there are multiple megacorps in this world, so in this world you could easily have in one city of 40 million people around 20 thousands boss like people just walking around. In other words plenty of Bosses for us the players to enjoy. Last detail on this point, also a medium megacorp could easily have far lower "quality" people than a Big Megacorp, so you could end up having lots of levels to go through and lots of bosses to enjoy, since at the beginning you may end up working for small megacorps and as your fame grows you could end up working for bigger and bigger corps until endgame.
Now even if you go and fight against a gang, the leader of the gang would also be tougher, do remember that in most gangs the boss is the one that gets a cut of the profits first and he also usually gets the bigger part, so having a gang leader with better mods would be normal.
Actually having boss fights in a game like cyberpunk 2077 is far more logical than in some other games, here you can see and relate the importance of a person is directly related to the quality of the mods that same person will have, you could close to endgames start encountering people who own experimental modifications that make them so freakishly tough, that either you fight smart or you die, remember this is a futuristic game is not post-apocalyptic nor medieval nor anything, people with money can and will try to get the best they can get with that money (we the players will also do the same).