The only way to get the battery life Framework advertised is on Windows' 'Ultra Efficiency' mode which cuts CPU performance by 25-50%, lowers brightness by 30% and deprioritizes everything in the background to such an extreme that responsiveness of those is measured in seconds.
It is not comparable at all to M-series or Snapdragon laptops happily chugging along at full capability and getting (compared to AMD / Intel) stellar battery life.