At the beginning of a TCP connection, which is when the certificate chain is sent, you can't send more data than the initial congestion window without waiting for it to be acknowledged. 160KB is far beyond the initial congestion window, so on a high-latency connection the additional time would be higher than the numbers you calculated. Of course, if the web page is very bloated the user might not notice, but not all pages are bloated.
The increased certificate size would also be painful for Certificate Transparency logs, which are required to store certificates and transmit them to anyone who asks. MTC doesn't require logs to store the subject public key.
The increased certificate size would also be painful for Certificate Transparency logs, which are required to store certificates and transmit them to anyone who asks. MTC doesn't require logs to store the subject public key.