> I just figure, everything is coming in as a string no matter what. It's going back out as a string.

Maybe so, but that only accurately describes things at the boundaries of your system. Your database tables still have columns that hold integers, dates, or floats. Sure, you could do the type coercions as needed, but at that point you're missing out on the valuable opportunity to validate your data as it enters the system. You can provide meaningful errors to users as early as possible, you can avoid defensive checks nearly everywhere else within your code, and you can just generally trust that invariants about your data are going to hold throughout the rest of your program.

This leads to smaller test suites, more concise codebases, and higher security assurances overall. If you look at the sorts of vulnerabilities that often pop up in Rails for example, many of them simply don't affect you if you use something like Virtus [0] to validate the types of your data as it enters the system.

I don't do much web development, but statically typed web development is the only way I've ever been able to tolerate it.

[0] https://github.com/solnic/virtus

You know what else takes in strings and spits out strings? A compiler!

Here are a couple of other under-appreciated facts about compilers:

1. For regular grammars, they are easy to build with any kind of programming language.

2. For regular grammars, they are really really easy to build with statically-typed programming languages.

Now days, my web development is essentially just compiler construction for regular languages, and it just so happens that extremely statically-typed like the MLs (F#, in my case) are damn good for writing compilers (one joke is that it’s the only thing they’re good for). I write far fewer lines of code per feature than I ever did with ”dynamically“ typed languages like PHP, and it’s usually right the first time.

You build your system as a box that takes strings in and sends strings out. You then have to do a bunch of checks (as part of your de/serializing) at the boundaries only. Inside the box, all your logic and transformations are type safe, and indeed you can turn some logic issues into mechanically checked type-level issues, which are basically free unit tests.

What typed languages have you used and what aspects do you find tedious? I find that the experience of writing brittle type-checking logic and tests in dynamic languages is rather tedious in its own right.

> I just figure, everything is coming in as a string no matter what. It's going back out as a string.

And everything in memory is a sequence of bytes. I don't see the relevance of this line of reasoning. I guarantee that whatever experience you've had with statically typed languages on the web, it's not a good language. Interfacing with dynamic systems is simply a matter of good abstractions, which many languages simply lack.

Take a look at F#'s type providers to see where you can go with this.

Yes everything is a string on the web, but IMO it's not the primitive data types that I'm concerned about so much - it's about the data structure (classes / interfaces). If I refer to my item's description property as `item.descripition`, statically typed language will scream that I have mistyped the property name before letting me run that code or, God forbid, releasing it.