The Efficient Market Hypothesis is not a binary, either the market is fully efficient or the market is not at all. There are 3 forms of market efficiency from classic theory: weak, semi-strong & strong form (the case of 100%).
It’s good to think of efficiency as a scale from 0-100% and on that scale the market is ~90%+ efficient (you can argue for less or more but it’s there or there abouts).
There are many puzzles & anomalies, some that are persistent, others that have been arbitraged away & others than can be explained by behavioural finance.
I’ll stop here, but the main point is don’t think of efficiency as being binary. Would defo’ be interested to read Robin’s response too.