Staking ROI (actual vs theoretical)

I noticed that my staking rewards are always around 20% less than what I would expect to receive.

Is it because the block time on mainnet (>6 seconds) is higher than the expected block time (5 seconds)?

Through a proposal, Cosmos Network adjusted the parameter “blocks_per_year” so that the reward rate align with the theoretical reward rate:

Do we expect the Secret Network to produce blocks at a faster rate than Cosmos?