I don’t know much about Spain or Italy, and I agree that Germany uses a lot of copper cables. But France and Poland? Esp. in Poland it most towns you have fiber, all new buildings have had fiber for ages. I currently pay 15–20€ / month for 1Gbps in a like 5th biggest city in Poland (not center, but not far either). In a couple of places in France I’ve stayed longer the internet was good as well (though I don’t recall the prices or exact speed details) — cities including Paris and towns. Granted this is all anecdotal and my bubble, etc.
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.
