Facebook is far from where Microsoft were in 2003-2007. Most people (90-something percent?) could chose between Microsoft or Apple or no computer at all.
Ordinary consumers could not use a text editor, a spreadsheet, send an email, or browse the internet, without doing it form either a Windows or Apple computer. Apple was a secluded niche for graphical designers and the like. Almost everybody else used a Windows computer. There were whole industries where everybody only used Windows operating system and the Office suite and where you could not work without.
Almost nothing ties me to Facebook and most businesses are not dependent on Facebook in any way. I can use computers, phones etc. without Facebook. I can contact people without it, write to them, see their pictures and videos etc. I can go online without. Most companies nowadays function perfectly fine without Facebook. If Facebook disappeared, only a few niches such as game studios, advertisers etc. would truly lose customers or the ability to work with others. Most advertising could be done through other channels in a matter of hours. Contacts with friends could be made in days using other platforms.
I was going to say that Facebook is where Microsoft were at some point in the late 70s or early 80s when it was just one out of several alternatives, but the comparison is just not good.