2100 is by no means a bad score - I myself got high 2100s several years ago - but it won't do you squat for "tier 1A" schools/Ivies like HYP, Stanford, and MIT. I've had friends with high 2200s and low 2300s get shot down by Ivies; it's a crapshoot even with near-impeccable stats, lower SAT scores don't help. 2100 doesn't bode well for the top "tier 1B" schools - Northwestern, UChicago, Duke, Cornell - these days either. (these 'tiers' are based on my own observations)
Yes, applications are generally holistic, and a good GPA can balance out a meh SAT and vice versa and ECs are important, but the fact of the matter is that you can get a good 'gut' feel for things based on the median accepted SAT scores you find in applicant profiles.