The Minna no Nihongo method could probably use an update. I mean... it's highly improbable in 2025 that you would need to go to the post office and ask if your stamp would be cheaper if you ship by sea rather than by plane. Also, the exercise directions are not always crystal clear: I sometimes struggled to properly understand what was expected of me, despite using it in a collective course. So a bit more clarity could be good, especially for solitary learners.
Despite these super tiny flaws, I still believe that this is the best method available. The units are well conceived, and its strongest point is that there is no romanji involved. With other methods, the romanji texts always catch my eyes, we instinctively look for it which delays progress. The Minna allows full reading immersion on this perspective.
If I might compare it to other methods:
Marugoto is way nicer visually, it's colorful and fun. But the content is less dense. It seems to me that while the Marugoto is great for learners who don't want to burn out (for example having only a little time to learn after exhausting days of work), the Minna is the best for people who want to go deep ASAP.
The Genki seems to be the biggest "competitor". I haven't used it myself but it seems that the main difference is having to learn verbs and conjugaison from the dictionary form rather than the masu form. Minna uses the masu which could sound a bit weird in some social contexts, but if you want to use Japanese for formal or professional situations, or would refer to sound a bit too polite rather than the opposite, Minna would be the best.
Another strength of the Minna no Nihongo is the available content around it. Tons of YT channels have awesome videos dedicated to each unit (Takashi's YT channel being my absolute fav) which makes the learning process way easier and nicer.
If you combine the Minna no Nihongo method with YT videos, a bit of other tools on the side (I recommend Renshuu, which teaches you the verbs in dictionary form, perfect to get you covered in all situations) and immersion in the way you like, you can definitively reach ambition goals in a class or by yourself.
がんばって!