Not having some way to gauge a player's hardware in a p2p game that can last up to 90 minutes (particularly dual gap) is going to lead to more toxicity, not less. Ping was removed because anything sub 500 is fine so long as you don't spike and most people do not comprehend that. It's why ping will show up as a yellow/red line if you do go over 500 ping.
What you could do is define some arbitrary cpu score value that is considered "bad" but that will always be subjective since it heavily depends on map and cannot be pinpointed objectively like ping.