We are some amazing individual scores these days in test. It's like single player contributing more than the rest of the team.
In recent India vs England, Shubhman Gill made 269 on first innings when the team made 587 and made 161 in 2nd innings. 400+ for an individual player.
Similarly we are in the day 2 of South Africa vs Zimbabwe 2nd Test match and Wiaan Mulder from South Africa has alone made 288 for team while the rest of the team has made less than that. With such a high scoring of over 500 on 2nd day and still plenty of wickets left, South Africa might bat the whole day and try to make Zimbabwe follow on.
In the end, Shubman Gill ended with a double century and Wiaan Mulder may get to a 400. And according to stats, Mulder's innings may seem more valuable than the one by Gill. But the fact remains that Mulder's innings came against a very weak opposition, while Gill had to face quality bowlers such as Chris Woakes, Brydon Carse and Ben Stokes. Matches such as this one prove that Zimbabwe is not fit to compete against tier-1 test nations, and should either remain in tier-2 or have their test status revoked.