The carriers offer a superfast download speed that is based off of mmWave: Verizon for example offers 5G Ultra Wideband: https://www.verizon.com/support/5g-mobile-faqs/

On my current iPhone 13 Pro I can get about 100 Mbps in San Francisco.

I remember having ~150Mbps with an iPhone 8 on LTE in 2017. Bandwidth itself has basically never been the limiting factor for the last decade or so. The problem is always data caps, and unless 5G/mmWave/etc is somehow magically exempt, it's not really a benefit (you can now burn through your monthly quota in seconds instead of minutes - great!).

You don't need mmWave for 100Mbps.

I have seen 2+ Gbps over mmWave.

"Regular" 5G can do hundreds of Mbps, maybe even 1 Gbps under ideal conditions.