I don't think there are any decent alternatives to replace TrueCrypt/VeraCrypt. There are some once you narrow the scope, like being fine with linux-only etc. With the same scope as VeraCrypt there's nothing better.
Additionally TrueCrypt has been out there and well known for a long time. It even had a pretty decent audit done. Even with its flaws this is a strong foundation to build on. Any brand new undertaking is pretty much guaranteed to have more flaws. Thus we should definitely focus on improving VeraCrypt. It would also be easier to do an audit on just the changes from TrueCrypt to VeraCrypt as opposed to a whole new program.
Additionally TrueCrypt has been out there and well known for a long time. It even had a pretty decent audit done. Even with its flaws this is a strong foundation to build on. Any brand new undertaking is pretty much guaranteed to have more flaws. Thus we should definitely focus on improving VeraCrypt. It would also be easier to do an audit on just the changes from TrueCrypt to VeraCrypt as opposed to a whole new program.