I'm at a 250 EE company with very small ops budget and I built a stable and modular account planning and CRM system (when we had 150 EEs) that uses structured + validated + protected Google Sheets for user inputs and some viz, Alteryx as the ETL, and Tableau (Reader) as the visualization. Took half a junior person and half a senior person to maintain it for 100 clients and 200 users. It has served well as a prototype for our Salesforce installation this year, which has enabled us to decommission half of the modules in the Google Sheets system. If we had gone straight from nothing to Salesforce it would have induced shock in most of our employees, and our data and processes would not have been ready to just drop into Salesforce. In my mind, that is the best use case for a spreadsheet 'app' ... build it from the start with the goal of it being a transitional tool to a 3rd party app, nudging users along the way to professional processes.