There are different types of obsolescence.

What you have is technically obsolete. There are (arguably) more advanced designs, materials, and manufacturing that enable better suspension, braking, shifting, ergonomics, etc.

An object becomes functionally obsolete when it is no longer possible or practical to maintain functionality. For instance, I have a 6 year old laptop that I can no longer find replacement batteries, processor chips, or screens if anything goes wrong. I can still surf the web and type emails to grandma, so although it was technically obsolete the day I bought it (it wasn’t the most powerful model in the lineup), it will become functionally obsolete when the parts to repair it are no longer available.

While your bike is technically obsolete (there may be better tools for the job), it is nowhere near functionally obsolete (it is an acceptable tool for the job). All of the parts you need to maintain it are readily available. I would even say that it is cheaper to maintain and easier to repair that what is currently available.