I never registered tools until I started buying Ridgid products. Unless a manufacturer specifies registration as a condition for them honoring their warranty, there’s no need to register. Such is the case with most tools I buy.
In the case of Ridgid, they offer an extended lifetime warranty free of charge for those who register their products, so I have registered several Ridgid tools, and I have had no issues at all with SPAM from them. In fact, I don’t recall getting any emails whatsoever from them; they have a message communication system embeded in their online registration.
Bottom line for me is, if I’m interested in a warranty to a particular tool, I read the warranty. If it specifies I must register the product to get their warranty, that goes into my decision to buy the tool or not. For example, it’s nice of Ryobi to honor a lifetime (correction: 3 year) warranty for their 18V batteries without requiring registration, and that went into my decision to buy their line of cordless tools. But I’m never interested in a warranty for anything I purchase from Harbor Freight.
FWIW, I do not want the government regulating how manufacturers warranty their products. Terms of a warranty should be up to the manufacturer to specify, and up to the buyer to choose whether to accept those terms or not. So far this has been the case, my hope is that it continues. We have excessive government oversight already. YMMV