We started using guides only in our 60s. I found them useful for getting my bearings where I can neither read nor write the language. I think it saved time, allowing us to see more. I also built in time for us without a guide or with a different guide.

One advantage is also learning more about the culture by conversing. I learned about rented wedding gowns, parental leave and so much more by talking to guides.

Our first/only trip to Japan last year was a good example. So I won’t be a Fodorite to give you a hard time for choosing to use a guide.

Did you really mean "guides" or did you mean tours?

I don't recall seeing posts knocking guides in Japan. When it comes to guides, I would expect someone to mention Goodwill Guides or similar. There have been car&driver and/or paid guides queries.

Not long ago there was a thread where tours were discussed and, unusually, slammed hard. Usually, someone will point out that Japan is good DIY destination and then the thread advances.