Yeah, it made everything very "real".
Irl, when something bad happens in a group, everyone helps how they can. Here, Shinomoya goes to her father, Izumo-tech guy thinks about asking his father (with whom he isn't in a good relationship with), military guy asks his ex-boss, Reno and Mina reassure Kafka, shark teeth guy tries to reassure his comrades, the vice-captain allows everyone to salute their savior, (who when it comes down to it, sacrificed his life for them). It's just a series of little details, but they sum up to make a good story. Kind of the opposite, of how these types of situations are handled usually in anime.

I too feel like this season should have been 24 episodes long to be honest, I don't know how they are going to round up everything in the next episode...
Some recent animes still go for 24 episodes, this season for example we had Dungeon Meshi, so making kaiju that long wouldn't have been that unusual either.

A bunch of anime still get the 2 cour treatment, recent ones off the top of my head;
Freiren, Dungeon Meshi, TsukimichiI, Spice & Wolf, Slime, My Hero Aca.

As long as they don't end on a cliffhanger I don't mind it being 12 eps, it is a shame though since it has just started getting interesting.

Worry not, the manga is still ongoing, so this isn't the last thing we see from this banger of an anime.