Having similar features doesn’t mean having a similar level of simulation complexity. What matters is under the hood, not in the buttons you press. PCs from the time wouldn’t even come close to be able to run airliners with today’s simulation complexity from the likes of PMDG, FSLabs, or likely even Toliss, Milviz, or Aerosoft (not talking about visuals, but pure CPU footprint of the systems by themselves).
Incidentally no. I don’t expect XP12 to die. P3D perhaps, but while it’s extremely unlikely that Laminar will be able to compete with MSFS on an even level, they have their fans and many of those will likely stick with it, probably plenty to keep the business running, if anything at least due to brand loyalty.