Languages do matter a lot. Yes, they are all technically equivalent, but the craft of software engineering is much, much more about social/cultural/community considerations than it is computational ones. What the community around a programming language values matters, because it informs a great deal about what's idiomatic in a language, what libraries are available, what kind of bugs are possible (or not), how easy code is to read, comprehend, and maintain, and much more.

What makes a language good is not what programs you can write in it, but how it constrains what you can do such that you naturally writing good code. For example, null pointer exceptions (or segfaults in C, etc.) are a classic problem that plagues many mainstream languages like Java, C#, Python, etc. In Haskell (and a handful of other languages, including Rust), null pointer exceptions are not possible, because nulls do not exist in these languages. Taking away this language "feature" actually increases the power of the language, because you can guarantee that a certain class of common bugs are not possible in your program. So languages that restrict known bad programming practices lead to programmers writing better programs and, more generally, a community around the language that resonates with these philosophies.