I don't see why it's either/or. There are a lot more legacy doors and stairs especially around the world, than there are people who could be helped with a climbing wheelchair or exoskeleton frame. And there's some infrastructure that might not be possible to upgrade, for historical preservation reasons.

Maybe the tech will always be too bulky, but it could also be rented out on location when traveling.

Accessibility ramps and accessible doorknobs are easy to empathize with. Most everybody is going to be in a situation where those are necessary or at least helpful at some point in their life.

Exoskeletons and climbing wheelchairs can help the people who need them on a regular basis. But when you hurt yourself so climbing stairs is an ordeal and need temporary accommodations, universal accessible design means those accommodations are already there, whereas there's probably not going to be climbing wheelchairs and exoskeletons easily available.

Doing both things is the way forward. It takes time for the built environment to change, but it's been about 35 years since the ADA passed and it's getting harder to find public buildings (in the US) without the basics like ramps, accessible doors, and accessible restrooms. This mostly happened without a lot of fanfare, but by enforcement over time; most jurisdictions will check for accessibility during the permit processes for building and occupancy permits; if not, the ADA provides a private right of enforcement.

There's no jurisdictions providing permitting for the digital world (except maybe app stores?); there's some ability to do private ADA enforcement, but it's not as established as for physical accessibility. There's also federal standards for municipal websites that are going to be in effect real soon now.