I work somewhere that was stuck in even more simple excel usage, like sorting a list and counting rows for each type of category instead of using a pivot table.

I've done some more advanced work with python and xgboost for some modeling, but the biggest improvements in terms of both time saving and regular use of data for informed decision making has been implementing basic reports and dashboards. So much so that sometimes I feel like I'm creating kindergarten doodles that get praised as amazing masterpieces, which is a weird sort of embarrassment. I jokingly describe my job as "I count stuff" because a big part of what I do is still working with departments on what they want counted and the most useful way of displaying it to them. Percentages and year-on-year comparisons are magic.

I'm not quite sure what qualifies as a "legacy industry", but just about any organization that's been around for 40+ years could have the potential for massive improvements from taking advantage of improvement made during <= the past 20 years.