Stripe Card: Treading a well worn journey similar to NewDay, who got big when they took over the Store card business that provided store cards to most major UK retailers (e.g. Debenhams, TopShop etc) And I think even that was originally set up by Debenhams and then services sold to others.
NewDay though has stayed independent and not linked up to any ecommerce platforms or even BNPL operators. Most UK PSPs could acquire for NewDay issued cards, which wasn’t aligned to Visa/MC or similar, making NewDay store cards easy to integrate to retailer websites and POS.
But NewDay have now branched out to white labelling scheme credit cards for major retailers (e.g. John Lewis transferred their white label Mastercard from HSBC to NewDay) as well as issuing their own Mastercard (with significant financial wellbeing tools on their portal, i.e. targeting their card to the less creditworthy; which means that some fraud tools wind up with higher declines for John Lewis card holders…).
Amazon phone service: well the UK’s largest MVNO is Tesco (well priced but not free, cross promotional loyalty deals), so Amazon could easily get into that business, why not, makes prime even stickier. Not with VMo2 (part owned by media rival Virgin Media/Liberty Global), but easily enough with BT-EE, Voda, or Three (and Three has been up for sale/merger for a while). Comcast’s Sky unit also MVNO’s; amusingly reselling minutes from VMo2 but that deal predates Telefonica selling o2 to VM. List of United Kingdom mobile virtual network operators - Wikipedia The MVNE and MVNO columns are the most interesting ; Transatel - Wikipedia would make that really easy for Amazon.
My friend @gireesh says MVNO is a waste of time for Amazon. I trust his judgment more than mine on this topic. I can see why they are trying.