It certainly sounds foolish at first, but what's the real risk? Is your employer really going transfer themselves your balance or snoop on your utility bills?

Now if you loaded a crypto wallet on your work device, that would be another story..

I know there are bad actors trying to get into my company's network. They are a high visibility target and have fallen victim to ransomware attacks before. Even if I trusted my employer, I don't trust what else may be lurking there.

You will probably find that your corporate TLS MitM proxy excludes financial institutions so that employees can do their banking without any doubt that their own company would respect the confidentiality of their finances. If not, your cybersecurity team needs some help.

Yes, when I was in charge of security at previous places we did not MITM a whole category of websites including banking, health, etc.