Why is Manchin the only democrat Senator leveraging the 50/50 vote split for the benefit of their state?

In theory, all 50 Democrat Senators can use their vote to demand something from Chuck Schumer or other Congressional leaders. But in practice we only hear about Joe Manchin following this strategy and he seems to be getting away with it quite well. But why don't more Senators follow the same tactic for the sake of their state? Is Joe Manchin the only Senator who's got very strong electoral prospects and doesn't need to worry about consequences at the next election?