You need to give them a tool that's as easy to use as a spreadsheet, and yet stores data in a relational database. There are plenty of spreadsheet-database hybrids in the market.
Using any tool but Excel has the same problem as finding programmers who are willing to use some obscure proprietary programming language. They're going to worry about career lock if they're not developing portable skills.
Even though Excel is proprietary too, it's ubiquitous enough that people don't have to worry about it.
What about a tool that tracks updates to shared Excel spreadsheet and replicate them in a SQL database?
And then, if somebody makes a change in the database, a trigger will update the spreadsheet
Such a two-way binding makes it possible to continue relying on spreadsheets for UX, all the while the data is not locked in there and we can also have other processes handling the data (a web app, some cron job, etc)
I don't use Excel much, but I do the analogous kinds of things with Python and Jupyter notebooks. The problem is that adding some kind of layer requires the involvement of corporate IT, which blows away the advantages of DIY'ing things.
That's true, nothing is as ubiquitous as Excel. But Excel is not designed for multiple people simultaneously updating data. At some point you need a database.
It's not perfect, but Excel can track changes by multiple users. Excel files shared on OneDrive/SharePoint allow multiple people to simultaneously update the data, and it tracks each individual change by each user.
I would say Airtable is. Or if your users are slightly more technical you can try https://visualdb.com/ because it lets you use your own Postgres instance as the backend db.
I feel quite comfortable in Excel - used various tools like Power Pivot, Power Query, OLEDB, created my own functions, Python within Excel, etc. - but Airtable felt so confusing and limiting. Other former colleagues also struggled with Airtable; maybe it was not explained to us correctly.
I’ve used Airtable a bit. I think it’s really cool and would like more people to use it. However, it’s a lot more clicks and key presses to get things done - especially data entry - than in Excel. This also makes it better, since you can put constraints on tables, for instance.
You are absolutely right about needing more clicks and key strokes in Airtable. You have to reach the pain threshold in order to look for alternatives to Excel. And how soon you reach the pain threshold depends on how big your data is and how many users are trying to modify the same data at the same time.
NocoDB is also a self-hosted option. I used it to power a family project that required regular API access, but without the rate limits of Google Sheets.