> This is expensive, but I found it to be the only viable solution to this problem.

Is it really? £150 on backmarket for a phone which will last 10 years doesn't feel expensive.

Makes sense to me to run any banking on a secure device anyway.

How is a pixel with grapheneos not a secure device?

Ps no it's not rooted but it won't pass full play integrity so it will usually be treated as such.

Also, a properly configured root is not a weakness just like having a computer where you don't log in as admin unless you really need to can be just fine.

A £150 back market phone is not a secure device. It probably stopped receiving security patches a month after its release.