First of all, like antithesis said, his promises are shit. Second of all, Trump objectively kept less promises than Obama (24% to 47% respectively).
https://www.politifact.com/truth-o-meter/promises/trumpometer/
https://www.politifact.com/truth-o-meter/promises/obameter/?ruling=true