Your fears are not applicable in my experience. Model-driven PowerApps are schema and workflow driven, using one set of tools. The plumbing is all standardised. Authentication, authorisation and license management integrates directly into the M365 infrastructure that large organisations already have. As for browser lock-in, this makes no sense - Microsoft Edge has moved to Chromium. In my experience, the trend is for internal IT to use these tools directly, but it wouldn't matter even if a consultant did the work - the solutions are built on a standardised stack fully owned by the business. I wouldn't be surprised if a significant percentage of LOB applications are built on this platform in the next decade.