Better is first and foremost opinion based so cannot be answered with a conical answer, but, will give it a stab anyway.
First, it is entirely dependent on application. Start with your suggestion of a 0,0 based coordinate system. This is used for many maps. It also has very little to associate it with reality as it is a two dimensional representation for a three dimensional problem. It works, somewhat, but for closer to reality the smaller of area that is being represented. It is "better" potential for reasonable speed surface travel and location applications like driving and walking.
Lat/Long is a navigational representation in three dimensions of a three dimensional situation. It becomes a far better solution for navigation when the curvature of the Earth and movement of the Earth becomes an issue. 204
Long range ballistics, air travel, ocean navigation, etc. These all do not work with a flat 2D representation of a 3D reality, they need spherical coordinates, and that is were lat/long came in. Spheres are generally measured in angles, not lengths. There are other factors in navigation such as the rotation of the Earth, but Lat/Long was the attempt to have a better system for those applications, and it is better. It is not actually what most would consider the best, but it has been around, known and used for a long time so is typically understood well by those who need it. It has drawbacks, like units (degrees, minutes and seconds) are not uniform size.
A truer representation would be a spherical coordinate system, but would this actually be better? It is a true representation in 3D of location, but one that for most people has little to no meaning. Who, for most applications, needs to know their position at any time as described by distance from and angle to the center of the Earth. It is a much better and needed method if say you are building a cyclotron that accelerated particles to a high percentage of the speed of light, but not for applications that most of us will ever consider. 204