Scammers create new accounts or hijack old ones and send out batches of messages that say things like "I am interested in your item, text me". Experienced sellers know to ignore anyone wanting your text number or email address, but new sellers may not. Even when eBay removes a scam account, the scammer will just create new accounts and keep sending those sorts of messages. And some sellers will fall for it and contact them in violation of eBay policy.
Scammers target low feedback sellers selling expensive items since they think that new sellers are less familiar with how eBay actually works and are more likely to fall for a common scam.
It is against policy for any users to exchange contact information prior to a transaction. This is meant to prevent such scams and other off-eBay transactions. Once a scammer has a seller's contact information, that can be used to send a phony PayPal email that makes it look like the seller has been paid.
Ignore anyone who wants you to text or send your email address prior to an actual transaction. If an actual buyer does not pay, file an unpaid item dispute. Consider listing items as fixed price with immediate payment required and not accepting offers.
