How Effective were Spears Against Cavalry?

[Flavivs Aetivs]

That's true, but in the case of the Late Roman Army their gear was issued - they could use the pay to modify it ofc, but they were supplied their armor and weapons and did not have to buy it themselves.

One of the hallmarks of a true professional army is that their gear is provided, through an equipment allowance or through actually supplying it.