Maybe it just works fast because there still are only a very limited number of users? And will speeds and latencies drop as the airspace gets more saturated?
In short - some but not really. 5G NR allows for extremely efficient resource block allocation and can handle ~10x more concurrent users than 4G. The latency should not degrade as long as the carriers don't do weird things with traffic allocation - the standard allows for ~4ms worst case latency.
I believe 5G handles congestion much better. But even if the speed drops, it will still be an order of magnitude faster than 4G. Absolutely worth it.