I have created my own solution that allows to DIRECTLY integrate Webflow with databases such as MySQL and MongoDB, as well as Airtable and others, without CMS collections.
I have created four very large applications based on this solution (written in backend, not JS!) and I can confirm that everything has been working for years.
The architecture is a bit more complicated, but it allows you to add all possible enterprise tools as well as 3rd party services.
I tried to explain everything on Youtube. Please check https://www.youtube.com/watch?v=7eXX4-G3sqU
If you have any more questions, feel free to e-mail me (email in profile) - thanks