Better yet, an RFID tag or BTLE beacon can be embedded cheaply.

Some pallets already have these types of chips embedded, and it has ensured these pallets are returned in most cases (and prevented pallet resale).

The credit doesn't appear of the packaging is stolen.

The theft is beyond the control of the recipient / customer.

That's my point.

OK, so if they're not scavenging for the deposit, why are they scavenging? Plastic isn't in short supply, there's not much resale value to it.

Who knows why it happens. The point being that in poorer neighbourhoods it very likely will, and many of the "just bill for it" approaches simply compound the underlying poverty problem.

Much the same way as such neighbourhoods are already food and retail deserts either because direct risks of operation are too high, or because insurers and/or banks won't back or support ventures there.

Paul Baran, co-inventer of packet-switched networking, wrote about the underlying problem in the 1960s:

https://www.rand.org/pubs/papers/P3780.html (footnote, p. 7)