Timothy Dalton makes the character his own
More than any other actor that plays 007, Dalton makes the character his own.
Prior to Dalton's interpretation of Bond, the character was pure kitsch and lacked depth, humanity, and realism
The Bond character of today is darker, deeper, more violent and introspective than the cheesy character of old. No actor contributed more to this shift that Timothy Dalton.
Dalton’s Bond showed a new side to the character. In License to Kill, Dalton’s Bond goes rogue, hell-bent on seeking his own revenge for the murder of Felix Leiter. This represents a significant break with the Bond of previous films and shows a more human, deeper character.  Bond becomes colder, killing people in more ruthless ways (he kicks Everett McGill headfirst into a shark tank and he set a villain on fire with gasoline). He is also far less composed (he pulled a gun by mistake on a small child with a bunch of balloons). All of this helps create a more rounded and believable Bond character. Someone in his line of work would have to be ruthless, and everybody makes mistakes by jumping to the wrong conclusion sometimes. We even get to see Bond cry at the end of License to Kill, showing an element of humanity previously unseen in the Bond franchise. Dalton’s Bond left a mark on the franchise and helped shaped the three-dimensional Bond character of today we all love.
Dalton’s human and “deep” portrayal of Bond robs the series of its trademark quips and fun. It makes it too serious. The car chase scene in The Living Daylights come across exceptionally flat without the humour and fun of previous Bond outings. Dalton’s delivery in combat makes Bond too riled up and angry to deliver humorous punchlines and jokes.
[P1] Dalton's performance added psychological layers to the Bond character
[Rejecting P1] Bond wasn't supposed to be psychological and deep, he was supposed to be funny and enjoyable to watch