In guitar manufacturing, CNC machines were a revolution. The quality of mid-range guitars improved massively, until there was little difference between them and the premium ones.
In furniture, modern manufacturing techniques drastically worsened the quality of everything. MDF and veneers are inherently worse than hand-crafted wood. The revolution here was making it cheaper.
CNC and other machining techniques raise the high bar for what's possible, and they have the potential to lower costs. That's it. They don't inherently improve quality, that's a factor of market forces.
The appropriate comparison is which is better for the same price
Particularly, furniture benefits greatly from hard wood. At least, the furniture that is old that you are likely to see. It also benefits heavily from being preserved, not used.
Generally incorrect, but it depends. Wear can cause mdf/veneer to have "bad optics" compared to solid wood, but mdf/veneer can have more suitable physical properties and enables more consistent visual quality and design possibilities.