Those could be seen as incremental, but from the top of my head the two biggest changes could be:

- foldables: they're a real game changer regarding where bikes fit and where they can go. Designs also tremendously improved and the cycling performance is really good nowadays.

- electric assist: it's not just adding a motor, a lot of work has happened to make the better of the it, and cargo bikes have become widespread mostly because of this.

Aluminum frames, disk brakes, suspension forks

Lots of the details have changes quite a bit. They might look somewhat similar, but a nice bike nowadays is mostly carbon fiber, and pretty aerodynamic.

There's been lots of innovation in the last 10-20 years, much less 100.

You don't think things like indexed gears, suspension, hydraulic brakes or lighter materials are innovations?

Even dropper seat posts are a useful recent innovation IMHO.

We just got an ebike. I rode slickrock on it last week and it was delightful.

Droppers are overrated (for me). Disk brakes are awesome. Bike weight (for mountain bikes) has probably gone up in the last 30 years. One by shifting is nice and the new front chainrings that keep chains on are cool.

Derailuers, Hydraulic brakes, Suspension, Lights, In hub Dynamos, Belt Drives, Gearboxes