For HFT? Absolutely not. For trading? The original poster needs to clarify what they mean by "trading" as this is probably still the case for most tech-driven prop trading firms.
You’d be surprised at how many traders and QRs in HFT (or at least in OMM) often reach for Excel. Granted this is way more common among older people in the industry. And as a technologist OP wouldn’t have to worry about writing or maintaining Excel scripts :p
Excel is a very effective tool for many things but suggesting that it would be useful to spend time learning Excel to prepare for HFT is really bad advice.
Yup mostly tech driven trading shops use technology that’s why they have competitive edge compared to banks