There aren't that many DC movies so I can take a stab at my opinions of which DC movies performed well vs those that didn't based on things I read, whats known of the budgets, etc.
1) MOS - met expectations. Made a lot more money than the previous Superman movie (Returns). A lot of people noisily complained about the violence/destruction and WB clearly listened leading to...
2) BvS - just below expectations but seemingly profitable. A movie bringing together the two best known characters in comic book history was probably expected to do Avengers level numbers. This didn't quite get there, but it still made a lot of money. Not a flop.
3) Suicide Squad - Way outperformed expectations. Made a huge profit despite middling reviews and generally negative public reaction. Also started all the rumors of WB meddling in movies as movie tone was changed post filming.
4) Wonder Woman - Mega hit. Successful at the box office, with critics, and with audiences.
5) Justice League - Made significant money, but still probably a loss. $661,324,295 worldwide is no joke - but a Justice League movie was definitely expected to do numbers comparable to Avengers movies. After all, this was the next appearance of Wonder Woman - and he solo movie made $822,963,408 worldwide. The movie also saw negative reviews on average. The worst thing to happen though was how this movie took studio meddling rumors (some confirmed) to a new level, with extensive reshoots changing the tone of the movie with a new director. The new tone didn't seem to match what came before.
Still, at this point the DCEU was 5/5 without a MAJOR flop, and arguably with only 2 box office "disappointments".
6) Aquaman - HUGE surprise hit. An unbelievable $1,151,961,807 worldwide gross. Anyone predicted $1,151,961,807 making more money than Superman, WW and especially the entire JUSTICE LEAGUE?
7) Shazam - Did ok enough at the box office to get a sequel. Generally liked by audience. Not a hit. Not a flop.
8) We're including Joker? Ok, another HUGE somewhat surprising mega hit.
9) Birds of Prey - Did the wheels start falling off here? Just $205,358,461 on an $84,500,000 budget. Not some kind of spectacular flop, but surely the studio expected more? Suicide Squad was a super hit at the box office, and many analysts ascribed that to Margot Robbie as Harley Quinn. Well, SS made $749,200,054 worldwide.
10) WW1984 - Can't judge the box office - it came out during the brutal winter covid wave and was released on HBO at the same time. Didn't do to well compared to some other day and date WB movies that came later, but this one was first and thus isn't fairly comparable to anything. So all we have to talk about is critical and viewer sentiment. 58% on RT and 5.4 on IMDB. Not scientific measurements in the slightest, but still definitely pointing to a negative audience and critical reaction - matching my anecdotal experience.
11) THE Suicide Squad - Another day and date movie, but later in the pandemic when more people had started being out and about. Still lost money theatrically despite being liked (90% on RT, 7.2 on IMDB) by critics and viewers, for the most part.
12) The Batman - A return to form at the box office for a DC movie - $772,245,583 worldwide. Not a part of the DCEU though, for which things were about to get so much worse!
13) Black Adam - $393,252,111 seems like a good box office for a villainous character movie without his main foil involved (no Shazam in this one). Still, the response by this studio seemed pretty negative, with rumors of The Rock leaking false information about the movie being profitable.
14) Shazam 2 - Uh oh. A bona-fide flop. Just $133,838,006 worldwide - a low number many couldn't imagine for a major comic book sequel just a few years before.
15) The Flash - Probably sealed the fate for any actors continuing their roles into the Gunn era. Despite some over the top early word of mouth calling it the best superhero movie ever, the audience and critical reaction was tepid, and the box office was a complete disappointment. $270,633,313 worldwide returns on a movie featuring the return of Batman '89? Shocking! Lets not forget that the actor strike and the tabloid hijinx of the lead could have played a role.
16) Batgirl - thrown in the trash by Zaslav. Lame.
17) Blue Beetle - This was meant to be a TV movie, so box office is hard to judge since the movie probably wasn't filmed with movie theaters in mind. Only made $129,288,072 worldwide though, so sadly its unlikely that this movie will be counted as being a part of the Gunn universe.
18) Aquaman 2 - Thrown into the world without even having a red carpet world premiere (probably due to the bad streak the DC universe was on, not to mention being the closing movie of the universe). So far its at $258,875,070 worldwide which is really quite good considering the circumstances.
So what's the miss rate? It's debatable because we don't know the details of studio expectations, marketing budgets, etc. Personally I would put the miss rate (didn't meet expectations or even lost money) at 50%. The 9 I consider misses are
BVS, JL, BOP, WW2, TSS, BA, Shazam 2, The Flash, Blue Beetle. Aquaman 2 will likely lose money too, but it never even really had a chance.
OK, I CONSIDERED doing this analysis on the MCU but this took forever to write and nobody really cares what I have to say. Perhaps late I will just type up a summary.