You've been told that having to collect sales tax will kill your business.
Think about it this way. You buy from Amazon ... you pre-pay for shipping, more than a hundred dollars a year ... then you pay sales tax in most states on many products, and you're not getting 40% off, are you? Has it stopped you from buying from Amazon? Has it stopped Amazon from becoming "Amazon"?
I've spent more than twenty years studying what happens when a retail brand opens a store in a new market and has to collect sales tax in that market (on online transactions). There's a modest, short-term hit to online business (mostly because customers shift behavior from online to the new store) followed by normal sales trajectory online.
When we sell something the customer wants to buy, sales tax is largely irrelevant.
Don't let third parties freak you out. Their narrative/agenda is designed to improve their business. Your job is to improve your business. Find some merch that your customers love and try harder to sell it, ok?