でもトワ様は外人からしたらセクシーディープボイスなんだ...

Multi-factor
She streams at good western timezones due to streaming early in the morning or late at night.
She plays a lot of western games like FPSs and hollow knight
She has a sexy deep voice that westerns can appreciate but incel beta nips are terrified of.
She's the best singer, and singing goes across language boundaries.
She's the cutest hololive with the cutest design.
She communicates with EOPs in a friendly way that makes them feel welcome without going out of her way to be memey.