However, "serverless" also comes with a heavy price to pay in terms of debugging your code. It works perfectly (more or less), assuming you can actually write perfect code. But can anyone in this world actually write perfect code?
The bigger and more complex your code base, the more difficult it will be to debug it, and the more difficult it will be to get it to work correctly in a "serverless" environment.
For some people, going "serverless" will make a lot of sense for them. Just like some people do fine with WordPress so that all they have to do is type out their content and outsource all the hard work for publishing a web site based on that content.
But you will also pay a higher and higher monetary cost for going "serverless", as you scale up. At some point, it will no longer make sense to outsource that to someone else, and you will want to bring that in-house.
Do you understand how locks work? Or plumbing? If you need to replace or rekey the lock on your front door, can you do that yourself? Or do you outsource that to a Locksmith? If you need to replace your toilet, can you do that yourself or do you outsource that to a plumber? What if your A/C unit goes out? What if your car breaks down?
There are going to be some things that some people are good at doing, and they're good enough at doing it themselves that they don't want or need to outsource that work to someone else.
And then there are going to be some things that those same people probably are not good at doing, and those should be done by someone else -- either outsourced, or someone else in-house who works in partnership with you.