This is already part of the tax code, also you need to report lottery and casino winnings. The only thing going on here is requiring a sales platform to "report" you at a lower level. But, if you make a profit on anything, or get paid for anything, or find a dollar bill on the ground you are supposed to report it and pay your taxes.
Don't get me wrong here, I think it's kinda carpy. But, I still remember the first time my buddy who's band I did sound for handed me a 1099 form. The thing which has changed is the reporting threshold, which previously was $20k and now reduced to $600, same as what my buddy had to report for paying me for side gigs.
I can totally understand why eBay doesn't want to incur the additional overhead of sending the 1099-K forms out to probably millions of more people than they currently have to. I can also understand why those of us who just sell a few machine tools or parts wouldn't want the extra hassle on our taxes of dealing with these forms.
But, if you read the IRS explanation:
Form 1099-K reports payments from payment apps or online marketplaces and from credit, debit or stored-value cards. Use it to help figure and report your correct income on your tax return.
www.irs.gov
You'll see it also covers a whole lot of other folks like Uber drivers and Air B&B hosts that have probably been skating under the wire for quite a while now.
In reality, if you're in the category of now getting 1099-K's you should also check your local and state tax guidelines to make sure you're not messing up by not paying taxes to them too.
Taxes are a pain, but they're the price we pay to have an orderly society IMHO.
So, my advice stands. If you get one of these forms you should discuss it with your accountant or other tax professional. You may find out that your "hobby" now qualifies as a business which will require additional paperwork on your part. You may also discover that some of the things you buy are in fact business expenses which could potentially offset the profit made from selling on eBay or another platform.
I'm not a huge fan of this stuff but I ran my own businesses for long enough to realize it needs to be taken seriously. Hopefully this campaign by eBay will succeed and the new lower threshold will be removed. But, seeing how broad it actually is I have my doubts.
John