According to Imam Abu Hanifa, the common factor in the like-for-like examples is that they are all sold/traded either by weight, or by volume. As such, only goods which are traded accordingly are susceptible to riba al-fadl; it would therefore be permissible to trade in unequal amounts any goods where the inequality is, for example, measured by counting or measured by length.
The majority opinion throughout the Hanafi school is that, when evidence exists thus, measure must be according to those means of measurement approved by the Prophet. For example, gold or silver — at the time measured by weight — could not be traded by counting or by volume, even if that is the custom of the land the trade takes place in. Whether or not any particular good is considered ribawi is based on its status at the time of the Prophet, even if these original means of measurement are no longer in practice.
However some scholars disagree — this is the position held by Abu Yusuf (one of the students of Imam Abu Hanifa) — and rule that equality of measure is to be according to whatever measurement is standard according to the local custom.
Also, given that non-fungible goods are not (typically) traded by either weight or volume, it also stands to reason that this would only apply to fungible goods.
In short, just because a good can be measured or weighed (which, as OP states, would apply to pretty much any physical good ever) doesn't mean that it's automatically ribawi; what matters is that it is a good that is actually traded according to volume or weight.
