How many distinct block template producers exist? We can’t know, but we know that six block template producers mine more than 95% of the blocks.

Are there pools with 40% of the hashrate today? No, but it’s assumed that AntPool & friends controlled about 40% of the network hashrate in 2023 and throughout the first half of 2024. Foundry had about 35% in early 2025. Currently, AntPool & Foundry each have more than 30% of the hashrate.