Are you talking about MS Office?

In my opinion, the user interface of modern MS Office is absolutely horrible.

I have used a lot of old MS Office versions, and until 20 years ago I thought that its user interface was very good.

Then there was a gap of about a decade when I did not need MS Office at work and I also had no reason to update my personally purchased MS Office Professional (which I was running on Linux, using Crossover, where it was more performant and more stable than on Windows; Crossover is a paid derivative of Wine, which ensures a better support for MS Office and for other professional applications).

After that gap, when I encountered again MS Office, I was shocked by how awkward its UI had become meanwhile.

Today I prefer very much the UI of LibreOffice, which is similar to the old MS UI, instead of the modern MS Office UI.

There are a lot of details that I dislike in the LibreOffice UI, but even so, I consider the MS Office UI much worse.

Because there was a time in the past when I was a heavy MS Office user, when using the modern MS Office I am aware about a great number of commands that exist, but I am no longer able to find them in the MS Office menus.

In the old MS Office, those commands were grouped in a way that was logical for me, so it was easy to find them even when I did not know where they were, because I had not used them before. But in the modern interface many commands are not where I would expect them to be, so there have been many cases when I had to do a random search through all menus, to locate them after a long time.