Based on the recent data from Common App, till Feb. 2021, among all the applicants applying via Common App, only 44% submitted SAT or ACT scores, which represents a huge decrease from last year, 77% in 2020. 
It's not that surprising since more and more universities have opt-in flexible application requirements on tests, plus the test cancellation due to the pandemic. 
Does this mean that when applying to those more selective schools, we'd really go for "test optional"? We are not so sure to jump to conclusions.  
Let's take a look of the numbers. For those applicants to more selective universities, the dropping rates of submitting ACT or SAT are actually lower than that of the less selective ones.