Just on the monitoring part, Go has nothing even close to VisualVM, Flight Recorder, JRebel, VM agents, JMX.
No mention of AOT compilers, JIT caches, and so forth.
Yes you could try to master it, but it takes years. If another tool compensates your lack of mastery, why not use it?
Many people like to write about how Golang is so simple, but the drawback of that simplicity is that many features of other languages are either covered by additional dependencies or by inflating code size. It's just as possible for Go projects to devolve into big balls of mud as for any other language.
For example, what do you think the following should print?
values := []int{4, 8, 15, 16, 23, 42}
for value := range values {
fmt.Println(value)
}
I also like the following one:
ch := make(chan int)
ch <- 1
fmt.Println(<-ch)
Golang is a fine language and simpler than most, but sadly "simpler" is not the same as "simple".
The Java standard library has a web server in it, it has JDBC. You could use those directly. That's comparable to the Go standard library. For real apps people don't do this because they want a lot more, like simplified database access or session management.
Look at this: https://pkg.go.dev/database/sql
It strongly resembles JDBC. Doing a database query with that is verbose and error prone. Compare the work needed to do a lookup query and map the results to a data structure with that to (Micronaut syntax, Spring is similar):
@JdbcRepository(dialect = Dialect.POSTGRES)
interface GophersRepository extends CrudRepository<Gopher, String> {}
var someGopher = gophersRepository.findById("goo");
Multithreaded collection types.
Configuring scheduling algorithms.
Pluggable services, cryptography algorithms, filesystem.
Sane way to manage dates, granted the original one was a bit clunky, but way better than parsing strings.
Sometimes I wonder if folks that criticise Java, and .NET, actually spend any time learning their standard libraries in practice.