Imagine being in a mcdonalds and everyone walks up and orders something from the cashier at the same time, that is what is going on here.
Why not make them form a line and take each customer one at a time? or 3-4...
Because that would be incredibly slow and customers would complain about withdrawal delays. It would also be costly (transaction fee wise) and bad for the Bitcoin network because they couldn't batch transactions.
It is pretty simple you set up a system where "if certain amount of users withdraw or alts are being traded and exchanged for btc which exceeds above normal a rate of traffic by 1.5x or 2x transactions" exec queue timer.
They are trying to support large scale API trading... bots, algorithms. Is that a realistic approach?
With the recent Binance hack of 7,000 BTC cyber security firm Ciphertrace pointed out that the reason hackers were able to obtain API keys, 2FA codes and other info was due to hacking hot wallets using a two factor approach, social engineering and SIM card porting of phone numbers.
If SIM card porting was required, then 2FA (with OTP authentication like Google Authenticator) is still fine going forward.