But this most likely has to do with the BTC price decline however, it's nothing new during a downtrend. We should see a traffic surge once again when the market has become extremely bullish just like what happened in previous bull runs.
Perhaps people whose place were restricted from binance took a refuge on those few exchanges that had an increased traffic -- just a guess.
I checked the link and it's about web traffic for cex, platforms that was most visited during the time the data was taken.. your guess might be correct or probably those cex seeing much traffic are giving users quality service and their reputation is growing.