(Vent) Why is this program so awful?

I have to use excel for work, I chart data and utilize these charts to show individuals progress, I'm told my chart needs some condition dividing lines to indicate when certain conditions changed so that the viewers of the data can see how these changes in conditions affect the metric of performance that I am measuring. All I need is to add in a vertical line on the graph with a little label above it. And then I just need to copy this over to a word document for the progress report. WHY IS THIS SO HARD? There's no options in chart options for this, ok lets look it up. "start by adding data points to your sheet for where you want your line to go-" STOP. Why would I ever want to add in data points to my sheet just to achieve an effect on a chart? I don't want anything but my data on the sheet. Eventually I accept that is the way I have to do it. Add the data points, set x to the date I want the line to show, set y to where it should be. Follow the video tutorial exactly. Nope, chart is now broken and unreadable. I try tweaking it to see if I can just get the data to show up right, no dice. Ok lets try the more impromptu way of adding lines by just adding shapes and grouping them with the chart so I can copy it over. Excel REFUSES to group more than 2 lines. I can manage to get one grouped but not the other for some reason and not the text boxes to label this. But the main point of this rant is just the question as to why I am having to do this at all? This program has existed for almost as long as modern computers. Excel should be capable of doing all the simple chart displays and adjustments without me having to jerry rig the solution. I get that utilizing all these smaller menus and data point tricks allows for more precision but my god I should be able to find an easy way to do this and not spend my whole afternoon chasing down something that works consistently! I guess ultimately my question is how do I add a simple vertical line on 2 dates in my chart but as a greater question why is this program the way it is?