you are correct about SegWit but let us not forget that the programs for using SegWit are not ready yet. or for example BIP173 is still in "Proposed" status, it is not even final yet!
Many other exchanges and services have successfully integrated SegWit months, so lack of native support from Core client is not an excuse.
and i completely disagree with "batching withdrawals". you say this now because they keep repeating it on reddit. but the same people who are repeating this will start attacking Coinbase when they hold their withdrawal to "batch it with others"....
I'm the one who say it on reddit, and I don't see any problems with it, privacy is already pretty bad when you withdraw from centralized services, so reducing fees by 80% is a very good tradeoff. And I haven't seen anyone complaining about batching ever, so I don't know where are you getting that from.
Meanwhile, the fees have dropped to 20sat/byte, because the trading volume is decreasing, but huge backlogs are going to happen again if companies won't fix their software.