I'd expect to see numbers: roughly how many projects he was using to draw his conclusions, how many people he talked to and general details about their level of

I'd expect to see numbers: roughly how many projects he was using to draw his conclusions, how many people he talked to and general details about their level of experience and domain of activity. Additionally I'd be curious to read what the concrete consequences of the monolith vs. microservices decisions were for those projects in delays, budget overruns, personnel churn, etc. Finally I believe that the types of projects are highly relevant - industry, domain, budget and so on. I would need the above to make my mind precisely because I can't find any indication that Fowler is a technical expert. The fact that they're a SW book author that I can't attribute any well-known software to is a big red flag for me. Likewise that they've been working as a consultant for a very long time.