What is the difference between strategies used in mid/low frequency vs high-frequency? I understand high-frequency is mostly stat arb but I haven't heard of to

What is the difference between strategies used in mid/low frequency vs high-frequency? I understand high-frequency is mostly stat arb but I haven't heard of too many quant funds that do mid/low frequency. I've seen one present before that used small changes in portfolio optimization to get an alpha of ~0.2% over the benchmark but that didn't seem too useful.