I had this argument 10-15 years ago, and agree about the potential for lock-in. But even at the time, I realized that I would rather not build Konqueror, Kate, or the Gimp from source, and would never make a significant change. They had become so complex that learning and keeping up with them enough to contribute would be a part-time job.

The current toss-it-over-the-wall-ware model is good enough. Android and Chromium technically "work" without Google, and their code is online. There are multiple Firefox forks. I don't know about OSS programs for Excel spreadsheets and Word docs, but I'm happy to sacrifice some freedom in order to never have to go down that rabbit-hole.