How does Apple still have so many of these first gen Apple wallets in stock? Did they really sell that poorly after people realized how easily the slid off the phone?
They slide off easily only depending upon what you’ve got on the phone. If using the bare back (shiny?) or something like an Otterbox Symmetry, yes can slide off if you shove your phone in your back jeans pocket. So try not to do that.
(edited) I use an Apple MagSafe Leather Case (see them for sale on Woot), and can tell you the genuine leather underside of the MagSafe Wallet and genuine leather case cling quite well, like a PBJ sandwich. I love my MagSafe Wallet with Find My support, so got a spare one here on Woot for my Pocket Tripod Pro and spare coffee shop card.
Your MagSafe wallet with Find My is a Gen 2 model, of which they improved the magnetic grip. Gen 1’s, like this listing, were horrendous and slid right off as you pocketed your phone whether it was bare or had a silicon or leather case attached.
This said, again I ask why Woot continuously only sells the Gen 1’s and never the Gen 2’s like yours with improved grip and Find My built in.
Because Apple hasn’t started releasing them at a price we’re willing to pay. 
Might be your experience, but not mine. As you can see from this pic, the magnets are almost identical from the Leather MagSafe Wallet (bought from Woot, BTW) on the left, and Leather MagSafe Wallet with Find My Support on the right. Maybe the “stem” of the lollipop is a couple of millimeters longer on the latter, but I find the adhesion is identical with same iPhone or same Apple Leather MagSafe Case.
If your experience was not with the Wallet on a bare iPhone 12, 13, 14, or 15, then I’d check your MagSafe case. Not all cases feature the full keyhole pattern of magnets — some have only the circle to aid MagSafe chargers (e.g. the Apple Leather Sleeve with MagSafe made for iPhone 12). (Oh, and some cases say “MagSafe compatible” or “wireless charging compatible,” only meaning you can still charge through the case, but the case has no magnets of its own.)
The 2gen (with Find My) units are likely still selling at nearly full price because they work with the iPhone 15, but don’t get grody after a few months use like the doomed Fine Woven crap.
