If someone cares: Context is BTW this good French train deal: https://www.hotukdeals.com/deals/sncf-carte-avantage-card-30-discount-on-tgv-tgv-inoui-intercites-incl-accompanying-person60-for-children-fixed-prices-for-last-min-4192915

Here in German: https://www.mydealz.de/deals/sncf-carte-avantage-karte-30-rabatt-auf-tgv-tgv-inoui-intercites-auch-fur-begleitperson-60-fur-kinder-festpreise-fur-last-minute-2223022 (and many other languages linked there, actually hehe)