You need to update your intel to 2019 where botnets cost peanuts and I can trivially rotate a tiny botnet of 100k IP addresses against your "solution", each IP addresses making a couple attempts. Modern script kiddie software has had that built in for over a decade.
Never had your /login forum attacked with {uname,pass} combos? This is exactly what the traffic looks like.
Never had your /login forum attacked with {uname,pass} combos? This is exactly what the traffic looks like.