1) second-hand goods purchased from a non-business are usually tax-free. With the exception of vehicles. You're asked to pay sales tax on these purchases when filing your income tax each year, but in practice, noone does this.
2) I buy used/refurbished tools and furniture pretty frequently. How exactly is the second-hand market being crippled here?
eBay was hit by special "marketplace facilitator" clauses in remote tax laws that have popped up since South Dakota v. Wayfair. The tax is actually imposed on the marketplace, not the seller. It doesn't matter what the seller's status is relative to the above, because it is eBay that is being required to remit he tax. If the seller is independently obligated to remit tax to a given state as well, they count the eBay-collected tax against their own obligation.
FB marketplace has the same tax requirement, so that only leaves cash transactions on craigslist now (which people probably wouldn't pay the tax even if were required).
But you can buy stuff on FB Marketplace or CL without paying sales tax, even if you use a service like venmo for handling payments. In most states, you are technically supposed to report these transaction on your income tax return, but enforcement of that is not practical for the state.