They didn't make those parts feel as emotionally serious as they should have because, as
@Chris Galindo said, the rest of the movie was such a joke.
Also, while Jane was in Endgame in a minor cameo, we haven't really seen her around in the MCU since The Dark World. So, we haven't seen her since 2013 and her storyline is rushed. It's like, "Hey, remember Jane? Yeah, she has stage 4 cancer! Moving on....". It felt like her story could've taken up an entire first act almost and we could have really delved into her character to get much more emotionally attached. Gorr also had a very emotional story that got undercut by the comedy imo.