The thing is, you don't always get that choice, at least in a way that wouldn't generate much opposition. If Spring Boot is what people use in most of the projects, opting for something else would generate lots of questions about that "inconsistency", especially as a part of the same team/project where services already exist that are written with it.
Same as not opting for ASP.NET with .NET, Laravel with PHP, Django with Python, Ruby on Rails, Express.js with Node.js and so on. Same as for picking .NET in a "Java shop" or Java in a ".NET shop" or even wanting to use Vue when most other projects are made with React etc. I'm not saying that Spring Boot is always the right choice (god no, honestly everything from Dropwizard to the likes of Javalin and Quarkus etc. have their use cases), just that you'd have to be able to make that choice yourself in the first place, which isn't always the case.
Same for Tika and other dependencies, which are often necessary evils: if you need to handle files and get their MIME types, will you just estimate what a file could be by looking at its extension, or do you actually want to look at the contents? And if you look at the contents, will you attempt the lazier approach ("Huh, this is an MS Office container type, no idea what's inside of it") or will you actually look for something more accurate ("Oh hey, this is an MS Office container type, with a Word document inside of it")? Then it becomes, do you want to spend the time reinventing that yourself or just have it done by the end of the day with an external dependency?
Not that Go is immune from that, you'd still probably want to just use https://github.com/gabriel-vasile/mimetype instead of building your own.
Aside from that, it's nice that Go isn't so "enterprise" oriented (yet?) and that the standard library is so strong (whereas Java only got a built in server around JDK 21 IIRC).
Edit: oh, also on my silly little list of jagged edges of Java, there's also the whole JUL, Log4j, Apache Commons Logging, Logback and SLF4J situation, whereas Go just has https://pkg.go.dev/log and it's nice. Not a horrible indictment or anything, I still use Java more or less daily, alongside other languages.