CSI and Surinder Singh Settled Status

We are in the process of completing an application for pre-settled status ( paper application for SS route).
In order for my wife to get the UK residence card, it was necessary for her to have CSI. I know there has been plenty of debate about this requirement but we just took the course of least resistance in order to get the card.
However, the application form makes no mention of CSI, so does she really need it?

She will need to apply again at the 5 year point for Settled status, presumably on the same form, so again, I fail to see why it is a requirement.

I wouldn't even have asked the question but for her insurer, Aviva, announcing job losses in the UK and it set me wondering.

Apologies but I should have mentioned that she needed CSI in the first instance because we came on the basis of self-sufficiency ( pension income for me, aged 66). That's still my only income but she has been working for the past 7 months.