(I haven't been hands-on with Fabric (I've used ADF and PowerBI pre-Fabric), and I work for a company that sometimes works with Fabric competitors, so I am biased.)

From our experience with customers, Fabric feels like a rebrand of existing Azure services, plus a few new beta services that Microsoft is aggressively selling to their customers as fully baked. I've heard two customer stories this year where they migrated ETL to Fabric and then had to scramble to migrate again because of latency or reliability issues.

I suspect Fabric will be pretty dang good a few years from now, and that it's probably a great option today for users who accurately understand its strengths and weaknesses, but I think the way some MS sales teams are selling the platform to customers right now is dishonest and harmful.