[hexane360]

Note that Mathematica units impose a very large runtime penalty, making them unsuitable for a lot of applications

[antononcube]

The applications that are WL-units suitable are much more than the WL-units unsuitable ones you refer to.

It is true that I (and others) avoid using Wolfram Language (WL) units. Or try to get the computation expressions units-free as quickly as possible. But that is also a normal procedure when crafting computational workflows.