It's not the trains that are the problem, it's the tracks. There are enough high-quality, high-speed trainsets to choose from (TGV, Velaro, ETR 500+, AGV, etc), but they don't have enough track to run them on.
Spain gets it. There, the government has invested an insane amount in a dedicated HS infrastructure which is used by all types of (high-speed) trains. Madrid-Barcelona is 3 hours and has already halved the need for the air shuttle that runs between the cities.
What we need is for governments to stop trying to do everything and do what they do best: Build the rail infrastructure according to the relevant standards (ETMS, ERTMS) and cooperate to fill the gaps in the network (Perpignan-Figueras, Lyon-Turin, etc). Then let private companies do what they do best: Run the trains, compete and drive down prices.