There are tools that do that, even more simply than Excel does. That's a separate issue, e.g., app discovery, corporate approval in some cases, and people unwilling to use the best tool for the job.
... No, my comment is specifically targeted at the example of making simple boxes, lines, and text. There are trivial tools for making diagrams where the barrier of entry is lower, and the ease of use is higher. I provided reasons why those tools aren't being used more.
The barrier to entry may be lower if you consider a user who has never used either software and is trying to make a decision. But if you have a user who has used Excel for the past 2 decades and is comfortable with it, low barrier to entry is still higher than just "go with what I know."