If that bike works for you, that's fine. it's NOT a REFERENCE point for how to get a mountain bike to fit and handle well for you. you're not comparing apples to apples at all here. it's just so far from what you have in mind that it makes no sense. it's like trying to decide what kind of hiking boot you want to buy based on your favorite flip-flops.
demo a few modern bikes that were designed with someone of your height in mind (when demos are possible again). ask around your local mtb community for someone that is close to your height and ask to take it for a spin. it will not fit anything like your current bike because it's not supposed to due to the very different demands from the terrain from what you're doing now. you can probably make any XL or XXL sized bike work better for you than what you have now without resorting to something extremely odd like a backwards stem, unless you have some sort of disfigurement that a doctor can diagnose like extremely short arms or a spine that is not conventionally mobile.
Last edited by mack_turtle; 01-22-21 at 03:38 PM.