So as an Australian I'd roughly rate them the same with BYD high end matching Tesla's high end and BYD having a low end that Tesla doesn't compete with (the Atto which is ~USD $15000 for a small electric hatchback has no Tesla equivalent).
So basically you either compare current NA/EU Teslas to a hypothetical untariffed BYD (I don’t think this is fair) or you compare Chinese made Teslas to BYDs (which of course leads to similar prive perf ratios).
The pricing page shows none available in the USA:
The interior is more taste dependent, but the Model Y Standard is clearly a low budget version (with fabric seats) that's below the BYD. The Model Y Premium interior and seats felt higher quality to me, but it has a more minimalist design while the BYD has a more traditional setup with a screen behind the wheel.
The Tesla screen/app seem more responsive and premium. Also above for example VW where things are often sluggish and don't feel as well designed from a UX perspective.