My view is that if you switch companies, and at the last you used SAP and the new one you have to use Oracle, it is going to be a learning curve with very little added value for you (except the fact that now you know to proprietary systems). With Excel, well, it is going to be the same Excel, just different data.

excel is flexible and easy for reporting/analysis for data of varying sizes from small to not ginormous whereas doing anything in an ERP requires an, often, low paid SWE with a thick accent in a different time zone at, comparatively, high cost and big delay

i.e., I can often solve problems in excel in an afternoon that would take months to solve with one of these SWE's