writes:

Victor airways are Class E airspace.

Yes. And Class E is controlled airspace. That's one of the distinctions
between airways and off-airway areas, and indeed, Victor airways are one of
the reasons for Class E. You need a clearance to fly IFR in Class E, and the
VFR minimums are more stringent. You can fly IFR without a clearance in Class
G, and the minimums for VFR are less strict. You can even do aerobatics in
Class G, with certain restrictions.

As I said, the invention of GPS is making Victor airways obsolete.

Since the airways provide obstacle clearance, they are unlikely to become
obsolete. That clearance is independent of the navigation method used.

Your faith in GPS-only navigation is worrisome.

There is nothing about a Victor airway that guarantees obstacle clearance
as they are defined by systems that only provide horizontal information.

No, they are defined as three-dimensional spaces that are clear of obstacles
within specified distances and tolerances. That's why all the Victor airways
have published minimum altitudes for every segment of the airway. Above those
altitudes, there should be no obstacles, so they are safe for IFR flight.

This remains true for these airways even if you choose to navigate through
them with GPS instead of VORs.

What guarantees being free of obstacles is looking at a sectional, which
is the same whether you are using Victor airways or GPS.

Looking at a chart tells you the minimum altitudes for the airways, and that's
what protects you.