It sounds like part of your decision was that Lambda comes out cheaper for hosting. That also doesn't pass the arithmetic I use to evaluate such things.

A dev, fully loaded, will cost you $200/hour. A half cage at a colo with a really fast machine in it will cost $800/month. So if you choose a stack that adds 4 hours of work each month (or 80 extra hours upfront), you're behind.

Given that (as I touched on above), your chances of outgrowing a beefy box in a colo (or its managed equivalent) can be thought of as zero until you see the big success event that proves otherwise, my money is still on boring tech and boring hosting.

Granted, Lambda is cool. I love building stuff on it for other people on their dime. But as a guy who also builds businesses on my dime, it remains a tool for tiny niche cases that can safely go down on a saturday morning without making me cancel my weekend.