I'm assuming 5G mmWave technology is like 4G and 3G technologies i.e. usually used with cell phone networks?
5G is probably going to end up in licenced spectrum, so will be more likely to be seen with commercial mobile operators. Not all 5G will be "mmwave".
"mmwave" is a term that matches frequencies in the 30 - 300GHz range. Rather high frequencies, with relatively short range. It will require a lot more masts or cell sites, so isn't likely to appear on day 1. It might end up needing base stations at each street, or on many lampposts or telegraph poles.
But a lot of cell sites will certainly add capacity.
I was wondering what is the ping like in those kind of technologies? Will 5G give as low a ping as fttp or fttc technology?
A good question. One of the links in my posts mention that EE's tests have had sub-5ms latency, end to end, which I guess qualifies.
I vaguely recall that I've seen one aim for 5G states 1ms latency, but that is seen as a "far-future" by operators.