Tit-for-Tat with occasional Forgiveness and occasional Defection (abuse of trust) often performs better than pure Tit-For-Tat, especially in the presence of random error. Tit-For-Tat falls into "permanent mutual Defection" tar-pit when playing against a Tit-for-Tat-like opponent that Defects once (perhaps in error) and is non-Forgiving.

Humans are pretty good at repeated-game theory, intuitively.

The ncase.me game goes into the forgiveness part

The success of tit-for-tat is a common misunderstanding; it is only the most successful within the makeup of Axelrod's tournament. The OP explains that the strategy is entirely dependent on the environment, and tit-for-tat may not always be the optimal strategy.