I’m not sure if they still do, but Amazon used to allow anyone with an account to review any product on their site, regardless of if they had purchased it from AMZ, or perhaps even if at all.
Therefore, the only thing that can be safely ascribed to the “Verified Purchase” tag is that the item was obtained through an AMZ transaction, ostensibly by the person writing the review. Nothing more, nothing less. There are still plenty of questionable, if not poor reviews that have that tag, and as illustrated, ways to circumvent the process and undermine its intentions.
This was instituted to try to improve the quality of reviews, but sellers still violate it.
Prior, certain categories were flooded by reviews where the opening sentence was “I received this for free in exchange…,” and while those have mostly disappeared, there are still reviews posted recently that make that admission.
Sadly, it’s hard not to take many “reviews” with a grain of salt, and it’s not just confined to Amazon reviews.