l know that age has to do with Fico score.At age 25 you will never have a perfect rating.BUT...does your Fico basically go bye-bye when you turn 70?
Suppose you get $2,000 or less from SS, and you have no pension plans or retirement savings.Suppose basically you're at poverty level.
Do old people like this have a chance in borrowing for a mortgage?
l do not worship the FIco score - I am just curious if old people can make big loans.

FICO scores do not depend on YOUR age - they depend on the ''age'' (and quality) of your credit history. Older people tend to use credit less, so their credit history, over time, may become less extensive.

Your FICO also does not depend on your income level. Older people tend to have longer histories and usually have much better FICO scores.

My 75 year old mother was able to refi her house based on her SS income (which is considerably less than $2K).

A 92 year old man was able to obtain a 30 year mortgage.

So no, fico scores do not factor in age

FICO does not care how old you are. They do care how old your credit accounts are or how long your credit history is. The longer the positive credit history, the higher your score will be. People with 800 fico scores tend to have 20+ years of credit history.