I've only shipped about 1,500 orders, the vast majority untracked, PWE, toploader. Only refunded 3 that were reported as not showing up eventually. Of course that's just anecdotal. USPS says they deliver more than 97% of mail on time, and of the remaining 3% most of it is late or damaged, not actually lost. That aligns with my experience as a buyer and a seller.

The way to guarantee tracking is to order $50 from one seller at once. TCGPlayer requires a tracking number to mark it shipped in this case. I am never going to track anything under $50, because that's a waste of money when I can take a 97% chance bet that it'll arrive safe and on time. Bubble + tracking, even limited to orders of $45+, would cost me 400% more than my expected losses over time.

Refunds are not a hastle at all. Not in the slightest. It's a button click, and one we expect to click every so many shipments and already subtracted from our expected revenue. It sucks, but it's going to happen to somebody. We know the deal to use the platform, it's buyer guaranteed and we want our 5 stars for resolving any and every dispute efficiently and fairly. Most claims are damage by USPS, only occasional late/lost, a few condition/version disputes or mistakes, and the occasional buyer who insists their card is fake (always escalate to TCGPlayer if this happens to you, as it's important that conterfeit claims are documented to catch anyone who is intentionally or negligently pushing them repeatedly, but in my humble experience, you're going to be wrong if it came from me. But TCGPlayer will do right by both of us either way, so don't hesitate if you're suspicious).

It could be worth raising this to your local post office. If it happens too much to you, you can get blacklisted from ordering. There could be something going on locally, and you want the post master to be aware so that if there is, they can resolve it.