I have a qr generator website that has been active for 10 years or more, during the last few years I have had random emails asking me to sell it. I've decline b

I have a qr generator website that has been active for 10 years or more, during the last few years I have had random emails asking me to sell it. I've decline because I don't want to lose the domain, maybe some of these buyers are motivated by this, not plastering it with AdSense which I always thought.