Shan Masood has the worst average for a top three batsman in Pakistan history (min 50 innings).
Imran Farhat, Yasir Hameed, Salman Butt and so forth. All these openers that were tried and failed were still better than Masood.
Masood is not an underachiever; he is just not good enough.
He is not the best choice for captaincy because he doesn’t even merit a place in the team.
My friend not sure about your basis for considering Yasir, Farhat & Butt better than Shan. Their overall average is marginally higher than Masood. In fact if you see below stats Shan's away average is better than these 3. In the current circumstances, I don't see anyone better than Shan for test captaincy. Originally he is an opener but he has let Imam & Abdullah opened in first 2 test and then Saim in 3rd test. We all know he is not the best batsman but at least he is trying to play more positive cricket with better SR. Yes, he has to play long innings otherwise like others he cannot survive for long. Probably he can come in middle order and score 70-80 quick runs
Shan Masood: 33 test,
4 100s & 9 50s. Scored 1 100 in England & Sri Lanka each & 2 in Pak, AVG: 28.67
Shan Avg @ Home 36.20, Away 30.27, Neutral: 20.37
Yasir Hameed: 25 test,
2 100s & 8 50s. Scored both 100s in one test match against Bang at Karachi, AVG: 32.41
Yasir Avg @ Home 43.23, Away 26.06
Imran Farhat: 40 test,
3 100s & 14 50s. Scored 1 100 in NZ, 1 against Ind at Lahore & 1 against SA at Faisalabad, AVG: 32
Farhat Avg @ Home 42.57, Away 27.52, Neutral: 30.83
Salman Butt: 33 test,
3 100s & 10 50s. Scored 2 100s in Aus, 1 against Eng at Multan, AVG: 30.46
Salman Avg @ Home 34.05, Away 26.57, Neutral: 53.25 (Only 2 test against Aus in Eng)