I'm an American, with experience in the US
Illegal Discrimination is determined by the jurisdiction you are in. Belgium will have different laws than than the US
Laws typically PROTECT vulnerable populations. Young people might be correlated with poor and uninformed, and there by entitled to protections. Likewise, Seniors may also correlate with underemployed and mentally impaired, and there by entitled to protections.
Note also that there is an important difference between the two scenarios:
1) 2 IDENTICAL products, but one is FREE 2) 2 SIMILAR products, but one exchanges convenience for cost
In the first example (similar to your example), one is DEFINITELY better (the free one), and CAN be targeted to people- because it is DEFINITELY better
In the first example (similar to my credit card), neither is DEFINITELY better than the other - it is a little more complex! And we have a higher burden showing that it is OK to offer JUST one to a protected class.
Accounts are often free to young people(<26)in Belgium, as well as in other European countries. Is that not discrimination?