Bitcoin can do about 3 transactions per second (TPS), though a bit more now potentially with SegWit active. Ethereum and new cryptos can go as high as 25 transactions per second. That’s a far cry from the 2000 TPS that Visa rams through every second of every day.
The initial reward per block used to be 50 bitcoins back in 2009. After about four years, this dropped to 25 bitcoins in late 2012. The last halving occurred in July 2016, and dropped the reward per block mined to 12.5. In 2020, this should go down to 6.25, in 2024, 3.125, and so forth, all the way until the reward drops to essentially zero.