Why are you multiplying it by the days in a year? Are you seriously saying that every single user will waste 72 seconds every single day when they use LibreOffice?
1. Regarding productivity tools, people tend to do roughly the same thing at work each day. What they type in might be different, but what they want the software to do doesn't differ that much.
2. People tend to be able to remember things from one day to the next. If I start using a new IDE, I don't have to spend an extra minute every single day for a year looking for the "build" button or shortcut. A user who works out how to format a line as a heading in LibreOffice won't sit around the next day, confused about how to format a line as a heading.
3. Regarding most commonly used functionality, the UI of LibreOffice is pretty intuitive for someone who has used any kind of office productivity software.
4. Regarding rarer functionality (e.g. Pivot tables) I would be surprised if anywhere near 100000 of those 120000 users ever use them. Most people just use a spreadsheet as a place to put tabular data, many don't even do simple calculations like summing with it. Most people just type big globs of text into word processors and do some simple formatting. Those who do use less common functionality tend to have the ability to work it out pretty quickly and either remember it or write it down.
As many have already said. The unfamiliarity problem you describe is the same with a new version of MS Office. When I got a new version of MS Office, I spent some time trying to find features that I used a lot before, but once I found them, I was back up to speed. If the timing of the change corresponds to the need to upgrade MS Office (e.g. existing version going out of support), then the disruption would be pretty much the same.
1. Regarding productivity tools, people tend to do roughly the same thing at work each day. What they type in might be different, but what they want the software to do doesn't differ that much.
2. People tend to be able to remember things from one day to the next. If I start using a new IDE, I don't have to spend an extra minute every single day for a year looking for the "build" button or shortcut. A user who works out how to format a line as a heading in LibreOffice won't sit around the next day, confused about how to format a line as a heading.
3. Regarding most commonly used functionality, the UI of LibreOffice is pretty intuitive for someone who has used any kind of office productivity software.
4. Regarding rarer functionality (e.g. Pivot tables) I would be surprised if anywhere near 100000 of those 120000 users ever use them. Most people just use a spreadsheet as a place to put tabular data, many don't even do simple calculations like summing with it. Most people just type big globs of text into word processors and do some simple formatting. Those who do use less common functionality tend to have the ability to work it out pretty quickly and either remember it or write it down.
As many have already said. The unfamiliarity problem you describe is the same with a new version of MS Office. When I got a new version of MS Office, I spent some time trying to find features that I used a lot before, but once I found them, I was back up to speed. If the timing of the change corresponds to the need to upgrade MS Office (e.g. existing version going out of support), then the disruption would be pretty much the same.