Or sometimes there's also fun options, like a map where you can place the strong player into the fortified center and they have to defend against three weaker players at the same time. That can serve as a handicap, but the asymmetry also just means that it's less obvious and therefore less frustrating, who's better.

Generally, I'm in favor of having such handicap features, of course, but I feel like it's even better when the game's design is just naturally less brutally competitive.
For example, in Gang Beasts, yes, you're competing with each other, but the weirdo controls mean that it's never entirely your own fault when you lose, and of course, everything is just less serious in general.

Ultimately, such handicap features will break competition, too, because rather than the weirdo controls or your stupid AI buddy, you can then blame the handicap. I guess, it also helps to not take games too serious in the first place...

Lastly, I'd like to throw in the objectively best handicap: Having to play cooperatively with the weak player.
Just don't compete with each other, but rather tackle a challenge together.