There's a difference between:
- Actions which are likely to kill the player if they're trying to do it when they're already low on resources or managing their resources badly
- Actions which kill the player if they do them wrong/at the wrong time
- Events which are likely to kill the player for the purpose of a set piece
- Actions which exist only to kill the player and do so immediately when you complete them for no reason other than "haha, now you're dead"
The missing rover is far from a death sentance. It's very easy to start tracking it down, go back to Laurion for supplies when you start getting low, then finish finding it in a single loop. You may find the reward lacklustre, but the pressure regulator is a huge buff, removing huge amounts of babysitting and time from all journeys for the rest of the game. Santorini's event is a set piece and the entirety of that facility's challenge. The tram is an existing action with other uses. Yes, it kills the player if they do it at the wrong time, but that's not its purpose for existing. And the obelisk, again, is a set piece and the challenge of the facility.
If you find the rewards for the rover and obelisk lacklustre, then I very much disagree. The obelisk reward has already been halved, and most people still think it might be a touch too strong, and the pressure regulator may be getting a slight nerf next update because it's always been too strong for how easily and early in the game you get it.
If you find these deaths abrupt and mood-killing, then I certainly don't think that adding more deaths with literally no benefit to doing them is going to help.