Chase, as well as most lenders, changes their lending portfolio constantly. Some companies, like American Express, maintain certain cards because of popularity or for historical reasons. One example is the American Express Green Card. This was their first charge card and is still in their portfolio because it's popular.
A simple Platinum card, on the other hand, has undoubtedly been surpassed in popularity by rewards cards like the Freedom
, and Ink cards.
If you want a comparable no-fees, no-rewards card that can have a high limit and low APR, check out the Chase Slate
card. It's a solid card for those who just want a no-frills credit card. Assuming you had some debt in the past, this card will also help you to stay out of debt with its management features, though I honestly don't know how good they are, as I don't have this card.
One good thing is the Slate card is available with low starting limits, such as $500. This can help you to rebuild your credit with a top-tier lender, as long as you have a good enough credit score and history to support a prime card.
If you're determined to have a no-frills Platinum card, US Bank does offer one and is advertised as having a remarkably low APR. I'd go with Chase though, because US Bank's online banking is a nightmare.
Scores on the mend...
FICO: 650 (Discover/TU, 6/23/2016)
Cards I Use Citi Double Cash, Chase Amazon, Capital One QuickSilver
Sock Drawer Discover IT, Citi Diamond Preferred, AE Visa, QuickSilver One, Walmart CC, CareCredit, CreditOne (keeping for history for now)
Short Goal Reach 680