This has absolutely nothing to do with burner phones and the proposed changes won't do anything to change that.
~5 years ago there was a big push (in the USA) to try and solve it with STIR/SHAKEN but I've not been involved or paid attention since then, so don't know if anything came of it. It's a legitimately hard problem to solve though. Lots of engineering and backwards compatibility technical problems, but also political, logistical and commercial issues are abound. You've also got some turtle issues too; it's attestation all the way down.