While I think fiber is technically better (if the last mile is passive), results are more important and by that metric Poland doesn't seem to be doing any better than its neighbors:
In both of these Poland ranks similarly badly (31st/43rd) despite entirely different data sources. France ranks slightly better but still pretty bad. Note that the first site lists median speeds, while speedtest.net shows averages.
Poland is still not that urbanized, so relatively large numbers of people living in remote places are for sure bringing the stats down. But, from what I've seen, in the cities getting 150 Mb/s, 300 Mb/s or even 1 Gb/s is common.
https://www.fastmetrics.com/internet-connection-speed-by-cou... https://www.speedtest.net/global-index
In both of these Poland ranks similarly badly (31st/43rd) despite entirely different data sources. France ranks slightly better but still pretty bad. Note that the first site lists median speeds, while speedtest.net shows averages.