What could have been...
Toby Fox is the creator of Undertale, but he got his start making hacks of Earthbound. It’s pretty obvious to Earthbound players just how much of an inspiration that game was for Fox, and Fox has been very upfront about the connections as well. Simply put, without Earthbound, Undertale probably wouldn’t have come about!
Since releasing Undertale and parts of Deltarune, Fox has shot to stardom in the gaming industry. His newfound recognition opened all sorts of doors for him, including the chance to meet up with Shigesato Itoi, the creator of Earthbound.
In a new interview (seen below), we learn that Fox originally had plans on asking Itoi about a new Mother game. Fox just wanted to know if Itoi would be interested in seeing a sequel, be it from Itoi himself or through fans. Fox even said that he would be willing to help make such a project happen in any way he could. The thing is, Fox never got around to asking Itoi about a sequel.
Fox said that Itoi seemed very happy with the success of Earthbound-inspired games, such as Undertale. Itoi even suggested to Fox that he should make Undertale 2! It was this interaction that helped Fox to realize that no one but Itoi himself could/should bring about a sequel to Earthbound, so Fox decided to keep the question to himself.
You can see the full interview in which this topic is discussed below.