That was basically my thought: there are plenty of programs which it can help (almost all business apps) but not all of those are limiting anyone’s work and the feature isn’t free. Having multiple true cores has been common for multiple decades now and I’d be really curious whether a modern chip design team would feel it’s worth investing in if they didn’t already have it. My understanding is that SMT has a power cost comparable to extra cores and given how well Apple’s CPU team has been executing I’d assume there’s been careful analysis behind not implementing it yet.