If I understand it correctly, Romania had no infrastructure (or an incredibly shitty one) and you guys had to build it from scratch, but since you built it late optic fibres were around and were relatively common
Nope, that's very far from what actually happened. What happened was that in the early 2000s, when the internet pretty much meant dial-up using Romtelecom's infrastructure, taxed by the hour and expensive as fuck, geeks started building neighborhood LANs. At first, they were solely for gaming and file sharing, but then they realised they could offer much cheaper internet than Romtelecom and its partners, because they would only have to get one internet line which could be used by all the people served by the LAN. In the mid 2000s, RDS started aggressively buying all these neighborhood LANs which by the time covered pretty much every city in the country. So for them, it was only a matter of connecting those neighborhood LANs to their data centers which was way cheaper than building their infrastructure from scratch. Using this strategy, RDS grew exponentially and competitors found themselves in a situation where they simply had to keep up with RDS (most of them failed miserably, including Romtelecom). RDS has since updated most of that infrastructure, but it was easy for them because by the time they needed to upgrade the infrastructure they already made a shit-ton of money and fiber became available from Chinese manufacturers on the cheap.
So, to sum it up, the reason Romania has such fast internet is:
- The lack of regulation which allowed really small companies to set up neighbourhood LANs (I doubt this would have been possible in most other countries where you would have needed to get a shit-ton of approvals)
- The fact that the government decided to drop Romtelecom's monopoly on communication infrastructure, which made it possible for a company like RDS to exist in the first place.
There's also our idiot government selling our state telecommunications company (complete with the infrastructure) to DT with a guarantee of a 5 year monopoly.
So, this is your problem right there. Drop Telekom's monopoly, deregulate and you'll have affordable 1 Gbps connections within a couple of years. If you maintain Telekom's monopoly, they will simply have no incentive to upgrade it, as other ISPs can't install their own to compete, so people would still be forced to use Telekom, wether directly or through another ISP which has to use Telekom's infrastructure.