It depends on the schools. For example Northeastern and BU routinely deny or waitlist many students with top stats while other students with equal stats are accepted with merit. You may want to look back on the Decision threads here on CC for schools that you are interested in. Many students post their stats and the amount of merit aid they received.
For example here is Northeastern’s decision thread:
http://talk.collegeconfidential.com/northeastern-university/2053431-northeastern-rd-2022-p30.html