He'd fit in terms of values. Steve stands for truth, justice, and the American way, which is not too far from what the Justice League represents. His physical abilities, while not as super as some of the League members, are still impressive and his combat skills would be useful.
It could be really interesting. Steve Rogers' sense of justice and leadership would blend well with the Justice League. His military tactics could help in planning battles against powerful villains. For example, in a fight against Darkseid, Steve might come up with a strategy to use the different powers of the League members effectively, like having Flash create distractions while Superman goes for a direct attack.
It makes his relationships complicated. New people he meets might not understand his old - fashioned ways. His relationships with his old friends are now just memories, which can make him distant in new friendships. But sometimes it also attracts people who are intrigued by his past - centric values.
There's also 'Bucky's Redemption in Steve's World'. This fanfic delves into Bucky's struggle with his past while Steve is constantly by his side, helping him heal. It shows their bond strengthening through various challenges they face in the modern setting.
One common theme is resilience. Steve Rogers is known for his strong will, and in these fanfics, he shows great resilience in the face of cancer. Another theme could be the support of his friends. The Avengers or other characters in the Marvel universe coming together to support Steve during his illness.
The team would likely be in a state of shock at first. They've come to rely on Steve's leadership and strength. His injury could make them more cautious in their actions. They might hold back on some missions until Steve is better.
The theme of adjusting to a new world also stands out. Steve is from a different era, and Bucky has his own challenges after his time as a weapon. Fanfics show how they navigate the modern world together, dealing with new technology, different social norms, and modern threats.