(Hated Meta Trope) Plot Holes that are not Plot Holes. There is an explanation if you bother to watch the movie

[u/KingZaneTheStrange]

"Plot Hole": Why didn't Thanos just make the universe bigger to end overpopulation!

Explanation: Thanos wants to kill half the population to end overpopulation right? If he created more resources, the universe would just become overpopulated all over again. He explains this in his villain monolog. There are parts of his plan that make no sense (he's called the Mad Titan for a reason), but this one is actually explained. His plan was also to punish people for their greed, and making more food would not be much of a punishment. He also has a savior complex which makes him double down on his plan to prove he's right

"Plot Hole": Why wasn't the Death Star's exhaust port fortified!

Explanation: It fucking WAS. They had laser cannons surrounding the port because the Empire knew it was a weak point. The imperial general saw the rebels and chose to do nothing about it. He says "I think you overestimate their chances". Luke needed help from Han Solo, the disembodied voice of Ben and the Force in order to get the torpedoes into that tiny hole. Han even says that the shot was "one in a million".

[u/Stoob_art]

The point of the death star is that it's an instant victory as soon as it fires. You can glass a planet from orbit but it will be a long and drawn out battle that could last weeks or months. Rogue one shows that the death star pulse doesnt have to blow up a planet and can very effectively just glass the surface instantly. It is used to destroy alderaan as a show of power, a way of saying "look what we can do whenever we feel like it".

[u/VillainousMasked → u/Stoob_art]

Not only that but you also have to consider planetary shields. If you want to glass a planet with a shield you either need to send in a ground attack to take down the shield generator, or spend an absurd amount of time bombarding it (for example, the generator protecting just the Hoth base was enough that the Empire launched a ground invasion to take it out rather than just bombard it from orbit, so a full planetary shield would be even harder to take out). The Death Star however would probably be able to blast right through a planetary shield.

[u/SirOutrageous1027 → u/Stoob_art]

To be fair, Rogue One only had the Death Star pulse sort of glass the planet to avoid contradicting A New Hope which references it being the first full test of the Death Star on Alderaan.

[u/MisunderstoodPenguin → u/Stoob_art]

There is also the fact that some planets have self defense systems like the canons on Hoth.

[u/AnotherStatsGuy → u/Stoob_art]

"We need a demonstration, not a manifesto."

[u/CryptographerNo927 → u/Stoob_art]

Eh idk with their tech i expect it wouldn't be too hard to attach q jump drive into a big ass asteroid and jump it into the middle of a planet.