Omnibus bills get made because it acts as the compromise document. Instead of promises to vote on separate bills, all the compromises are lumped into one bill to vote on.
It is also important for a Congressional system like the US, with two houses with their own democratic mandate and an executive who can veto. Most countries have a Parliamentary system, or at least a different kind of system without the stark division of powers that the USA has.
Omnibus bills get made because it acts as the compromise document. Instead of promises to vote on separate bills, all the compromises are lumped into one bill to vote on.
It is also important for a Congressional system like the US, with two houses with their own democratic mandate and an executive who can veto. Most countries have a Parliamentary system, or at least a different kind of system without the stark division of powers that the USA has.