the sadist type of player

I've got a theory about the players who gives you extra time when they are winning. They delude themselves thinking they do it out of generosity, but they don't... They want to enjoy seeing their opponent in trouble, they want to prolongue the agony and the extasis of checkmating him. It is sadism, not generosity. They will never give you extra time when you are winning but having problems with the clock. Hey, I dont want your miserable extra seconds!

The + time feature needs eliminating. It only leads to abuse.
Possibly a feature made available by request, but to allow players to automatically add time to your clock without permission is ludicrous.
It is a built in "option" that invites abuse as players are known to + time at the start of games.

Michael Stean describes in his 40 years old wonderful classic „Simple Chess“ that every chess player has such inclinations. Scenario: When the opponent frantically tries to evade the mate in three and we just lean back and watch him fail.

An argument could be made the player who does not resign is a masochist.

It is a good feature. Sometimes you need to add time for coaches/streamers, when they need time to explain something. Suggestions to make it "per request" would allow trolls to ask for time multiple time. IMO there should be an option to disable it. If you enable it, people can add time , if not no time adding.

Here is the deal when it comes to adding time.

You are never required to use any time given to you. Lets say I'm having a blitz game vs someone. They click, click, click, click... and add 20 minutes to my clock. I don't NEED to use any of that time. I can move super fast, or resign if I choose to do so.

I'll set up some scenario's where it is used in a psychological manner.

Scenario 1: You are in a resignable position. Checkmate is coming soon, but your clock is running out. They toss you a little time so as that they beat you by checkmate, or you resign.

Scenario 2: They have a small advantage in position, but a little bigger one on clock. They want to be able to think on your time. Often times when you toss someone time in such a position they toss some time back at you as a thank you.

Scenario 3: They have a small disadvantage in position, but by throwing you time it takes you off guard. "Why are they giving me time? Are they better? What do they see that I can not?" This can cause one to stop briefly and think, or rethink things, and possibly make an error.

Scenario 4: It's a good game, sporting and both sides have chances. Tossing them time here can either get them to give you time back, or use that time so you can come up with some plan.

Scenario 5: They know you are one of those "never resign" people, and you are not moving so quickly. They want to checkmate you.

Scenario 6: They just made a subtle blunder. Many people move right away, or a few seconds after being given time. By throwing you time it could make you think "clock", and move right away so you do not capitalize on this blunder by calculating it out.

The issue is simple.
Unless requested or it is known in advance, by example a "coach" wants to add time, it never should it be an option to add time.
As suggested, the best solution is to make available an option to disable it. If both players leave the +time feature on then it applies, if one player disables it, then the option becomes unavailable.

Lichess missed the boat on this. Nowhere else on-line or OTB can time be added WITHOUT the opponents permission.

Why would you care if someone added time to your clock? That's seriously bizarre to me to be upset about.

If someone doesn't want to win on time or think the opponent may lose as he is lagging, to make the game somewhat fair.

Well, I’ll take it as yet another hobby player quirk like take-backs and rematch-enforcers and further of such „semi-illegal“ things.

A good player simply sticks close to the FIDE rules, others are hobby woodpushers.