Why do you think Solo underperformed at the box office?

I'd say the last one, no matter how much TLJ haters try to spin it as that movie's fault. People were mocking of and disinterested in this as soon as it was announced.

I'll say this, I've been extremely excited about every SW movie before this one and I saw it during its first or second day. But I still haven't seen Solo. I'll probably see it in a week or 2 if I feel like it? but even with the improved trailers I realised, when it came out, that I didn't care that much. I didn't have the need to see it during the first or second day. I will probably be very excited about episode 9 so this isn't something against the sw movies in general. I just don't really care about the Solo movie that much and I think many other people feel the same.

Most movies would kill for a weekend like that.

Identity politics

A bit of franchise fatigue

The "We Remember Chuck Cunningham Society" radicals sabotaged it.

An awful lot of them do:

1 Pirates of the Caribbean: On Stranger Tides 2011 *$378.5 [1][nb 1]

2 Avengers: Age of Ultron 2015 *$365 [2][nb 2]

3 Avengers: Infinity War 2018 $316 [3][nb 3]

4 Pirates of the Caribbean: At World's End 2007 $300 [4][5][nb 4]

Justice League 2017 $300 [6][7][8]

6 John Carter 2012 *$263.7 [9][nb 5]

7 Tangled 2010 $260 [10][11][12][13]

8 Spider-Man 3 2007 *$258 [14]

9 Harry Potter and the Half-Blood Prince 2009 $250 [15][16]

The Hobbit: The Battle of the Five Armies 2014 $250 [17]

Batman v Superman: Dawn of Justice 2016 $250 [18][19][nb 6]

Captain America: Civil War 2016 $250 [20][21][22]

The Fate of the Furious 2017 $250 [23][24][25]

Solo: A Star Wars Story 2018 $250 [26]

15 Spectre 2015 $245 [27][28][nb 7]

Star Wars: The Force Awakens 2015 $245 [29][nb 8]

17 Avatar 2009 *$237 [30][nb 9]

18 The Dark Knight Rises 2012 $230 [31][nb 10]

Pirates of the Caribbean: Dead Men Tell No Tales 2017 $230 [32][33][34]

20 The Chronicles of Narnia: Prince Caspian 2008 *$225 [35]

The Lone Ranger 2013 *$225 [36][nb 11]

Pirates of the Caribbean: Dead Man's Chest 2006 $225 [4][37][nb 4]

Man of Steel 2013 $225 [38][39][nb 12]

The Hobbit: The Desolation of Smaug 2013 $225 [40][41][nb 13]

24 The Avengers 2012 $220 [42][43][44][45]

26 Transformers: The Last Knight 2017 *$217 [46]

27 Men in Black 3 2012 *$215 [47][nb 14]

Oz the Great and Powerful 2013 *$215 [48][nb 15]

29 X-Men: The Last Stand 2006 $210 [49][50]

Transformers: Age of Extinction 2014 $210 [51][52][53]

31 Battleship 2012 *$209 [54]

32 King Kong 2005 $207 [55][56][57]

33 Superman Returns 2006 *$204 [58][59][nb 16]

34 Titanic 1997 *$200 [60][61][62]

Transformers: Revenge of the Fallen 2009 *$200 [63]

2012 2009 *$200 [64]

Spider-Man 2 2004 $200 [65][66]

Quantum of Solace 2008 $200 [67][68]

Terminator Salvation 2009 $200 [69][70]

Toy Story 3 2010 $200 [71][72]

Green Lantern 2011 $200 [73][74][75]

Cars 2 2011 $200 [76][77][78]

The Amazing Spider-Man 2012 $200 [79][80][nb 17]

The Hobbit: An Unexpected Journey 2012 $200 [81][nb 18]

Iron Man 3 2013 $200 [82][83][84]

Monsters University 2013 $200 [85]

The Amazing Spider-Man 2 2014 $200 [86][87][nb 19]

X-Men: Days of Future Past 2014 $200 [88][89][nb 20]

Rogue One: A Star Wars Story 2016 $200 [90][91][92]

Guardians of the Galaxy Vol. 2 2017 $200 [93][94]

Star Wars: The Last Jedi 2017 $200 [95]

Black Panther 2018 $200 [96][97][98]

Only twelve of those did, so I'm not sure why you felt the need to list the other forty of them.

And how many of those had the same opening weekend number? And were considered a success?