Every region should build the public transit it needs and can afford. The most boring, proven transit won't win beauty or speed awards or attract tourists but gets people cheaply from A to B and boosts the economy. To build a high speed connection, you have a certain economic start-threshold where the investment amplifies the economic output enough to benefit the region and not suffocate it in debt before it can flourish. So I'd expect more high speed rail between economically well faring regions, which increases the 'euro per person' but could be the same or less spending relative to gdp or avg. income.

Equality discussion aside: the spending discussion needs to be split in maintenance and expansion. Regions with currently more rail should be spending more on maintenance than those with less. Underinvestment in this area means decay, so to see decay of german rail compared to swiss rail, you need to compare how much they spend on maintenance, and normalize to account for differences in bridges, tunnels, high-speed, low-speed, single track, etc.

Expansion is a differrent beast, especially because the price decreases if you build steadily every year and economies of scale kick in. If only our polititians would get that... RMtransit made some good videos how to decrease the costs of transit expansion.