From the brevity of your Descriptions, are you listing on your phone?
The phone app, I understand, defaults to the Simplified Sell Your Item form, which in turn defaults to Best Offer on all listings.
If you switch to the Advanced Form, which gives many more options, Best Offer is an option not a Default.
That being said, there are complaints that eBay is adding Best Offer to listings that go "too long" without a sale. I have very long-tail items, and I haven't seen that yet, but there have been reports.
Remember you can counter -offer, decline, or ignore any Offer. You can also set your Seller Preferences to automatically decline any offer under your chosen amount or percentage. (Some seller raise their prices to allow *for Best Offers.)
*The seller gets her price and the buyer gets his "bargain". Win/win.
