It depends on what you are comparing it to. Preferential voting (aka ranked choice or alternative voting) is less favourable to bigger parties than first past-the-post is. But it is more favourable to bigger parties than other systems such as single transferrable vote (STV) or mixed member. The biggest reason why Australia hasn't moved to STV or mixed member for the House of Representatives, is that doing so would benefit smaller parties at the cost of the bigger ones.

> Use of the word gerrymander in this way ("having boundaries at all is gerrymander") is meaningless.

An STV or mixed member system would still have boundaries, but would be less advantageous to the bigger parties. Why isn't choosing a system which is intentionally more advantageous to the bigger parties a "gerrymander"?