“But in each case they have added something to Sola Scriptura to justify what they are doing.”
So sola scriptura is essentially useless since it is all subjective to the individual.
The term ‘Sola Scriptura’ commits the fallacy of the undistributed middle ... which is perhaps why Catholics are fond of it since it then allows them to insewrt the authority of the priests and the councils and the Pope and Mary, and ... well, you get the gist. The term wouldn’t apply to the era of Paul when he was evangelizing and writing letters, but that doesn’t stop some from using the fallacy to their agenda aims.
I don’t understand how you got from my statement to Sola Scriptura being essentially useless. Just because some people twist scripture to their own demise, does not mean the scripture is the problem