Yes, I understand very well that "research" is a pipe, where you put billions of euros in one end, and get stack of papers on the other end. And somebody becomes rich in the process. Sapienti sat.
You are counting from some early planning phases. Compare, for example, how long it took for the UK to build High Speed 1 line.
It's worth noting that the non-HS standard gauge (part of Rail Baltica I) between Poland and Lithuania (up to Šeštokai Intermodal Terminal) was completed back in 2015. The freight trains have been operating on this line all the time.
Yes, I understand very well that "research" is a pipe, where you put billions of euros in one end, and get stack of papers on the other end. And somebody becomes rich in the process. Sapienti sat.