This is not all telling but you can sort 2-man line up stats.  I sorted by the best total +/- for each team:
1. UTA  Gorbert/Conley       1368 min / +528
2. PHI  Embiid/Simmons     1164 min / +393
3. LAC  George/Leonard      1028 min / +378
4. DEN  Jokic/Murray           1363 min / +339
5. MIL  Giannis/Middleton   1452 min / +322
6. PHO  Booker/Bridges       1870 min / +279
7. GWS  Green/Curry           1738 min / +278
8. POR  Covington/Lillard    1805 min / +257
9.  ATL Collins/Young         1455 min / +239
10. BKN Irving/Harris         1293 min / +196
11. MIA Butler/Robinson     1177 min / +190
12. MEM Valanci'/Brooks      1314 min / +165
13. LAL  James/Schroder      816 min / +162
14. NYK Randle/Bullock       1811 min / +122
15. NOP Williamson/Ball      1114 min / +112
15. SAS Poeltl/Murray         1307 min / + 106
16. TOR Siakam/VanFleet    1466 mn / +96
17. BOS Tatum/Brown         1263 min / +79
There are a number of top duos that either didn't have the minutes to qualify for my sort or that were on lesser teams that just didn't have the same level of +/- success.  Also, for many of the teams, they had more than one 2-man group that did very well.  For example, Utah had 7 of the top 10 and Gobert was part of 6 of those 7.  Again, I just listed the top one for each team.
I also note that most of these duos include one big.  12 of the top 17.  I did a per 36 sort to normalize against time but that really did not change things all that much.  Utah/Gobert were still most of the best duos.  Harden and Durant are clearly a top duo but this didn't make my sort due to not enough minutes on the floor together.   Lillard/McCullom were 1068 min/+221, not the best on POR for total but best per 36 on POR.
Tatum and Brown did not fare so well in this comparison.
Above is a tell-tale sign. It's all about making the players around you better, pushing them to be the best they can be. Just as this real plus/minus comparison is:
1   Stephen Curry, PG   GS   63   34.2   7.08   0.10   7.18   19.05
2   LeBron James, SF   LAL   45   33.4   4.63   2.10   6.73   11.91
3   Rudy Gobert, C   UTAH   71   30.8   -1.45   8.00   6.55   16.52
4   Paul George, SG   LAC   54   33.7   1.55   3.89   5.45   11.98
5   Giannis Antetokounmpo, PF   MIL   61   33.0   3.89   1.20   5.09   14.03
6   Nikola Jokic, C   DEN   72   34.6   3.12   1.96   5.08   15.85
7   Joel Embiid, C   PHI   51   31.1   2.04   2.98   5.02   10.01
8   James Harden, SG   HOU/BKN   44   36.6   3.99   0.98   4.97   9.94
9   Damian Lillard, PG   POR   67   35.8   3.88   1.09   4.97   14.55
10   Lonzo Ball, PG   NO   55   31.8   3.19   1.27   4.46   10.06
11   Mike Conley, PG   UTAH   51   29.4   1.25   3.12   4.37   8.28
12   Fred VanVleet, SG   TOR   52   36.5   1.27   2.78   4.05   10.67
13   Kyle Lowry, PG   TOR   46   34.8   2.90   1.12   4.02   8.98
14   Kevin Durant, PF   BKN   35   33.1   4.07   -0.11   3.95   6.06
15   Devonte' Graham, G   CHA   55   30.2   1.92   1.97   3.88   9.24
16   CJ McCollum, SG   POR   47   34.0   2.09   1.78   3.87   8.42
17   Ben Simmons, PG   PHI   58   32.4   1.28   2.39   3.67   9.80
18   Chris Paul, PG   PHX   70   31.4   0.48   3.06   3.54   10.78
19   Jamal Murray, PG   DEN   48   35.5   0.41   3.07   3.48   8.04
20   Kyrie Irving, PG   BKN   54   34.9   2.96   0.49   3.44   9.16
21   Jimmy Butler, SF   MIA   52   33.6   1.50   1.90   3.40   8.70
22   Julius Randle, PF   NY   71   37.6   -0.76   4.16   3.40   12.36
23   Joe Harris, SF   BKN   69   31.0   -0.60   4.00   3.40   10.14
24   Clint Capela, C   ATL   63   30.1   -1.63   4.98   3.35   9.12
25   Zion Williamson, PF   NO   61   33.2   1.07   2.13   3.20   9.45
26   Christian Wood, C   HOU   41   32.3   0.54   2.60   3.14   6.19
27   Bam Adebayo, C   MIA   64   33.5   -0.77   3.78   3.01   9.56
28   Luka Doncic, PG   DAL   66   34.3   2.44   0.51   2.96   10.37
29   Duncan Robinson, SG   MIA   72   31.4   -0.56   3.45   2.89   10.04
30   Terry Rozier, SG   CHA   69   34.5   1.29   1.59   2.88   10.77
31   Jaylen Brown, SG   BOS   58   34.5   2.10   0.71   2.81   9.39
32   Danny Green, SF   PHI   69   28.0   -0.87   3.67   2.80   8.28
33   De'Aaron Fox, PG   SAC   58   35.1   2.92   -0.27   2.66   8.85
34   Kyle Anderson, SF   MEM   69   27.3   0.16   2.44   2.60   7.82
35   Jrue Holiday, PG   MIL   59   32.3   1.80   0.77   2.57   8.64
36   Kawhi Leonard, SF   LAC   52   34.1   1.46   1.10   2.55   7.55
37   Donovan Mitchell, SG   UTAH   53   33.4   3.26   -0.76   2.50   7.52
38   Zach LaVine, SG   CHI   58   35.1   1.82   0.65   2.47   8.78
39   Tobias Harris, PF   PHI   62   32.5   -0.20   2.65   2.45   8.21
40   Jayson Tatum, SF   BOS   64   35.8   1.06   1.39   2.44   9.60