Installing an "office suite" these days is becoming less and less of a need. I can only speak for myself, but online versions at Google, or Microsoft (to mention two) are all I need.
Google implementation of an office suite is very popular at middle, high school, and online universities (even though most of them offer the free Office365).
So, speaking for myself, I wouldn't trust these online office suites with my data or time. They also tend to lag more on lower-end hardware (I frequently use a netbook for notes, etc).
I had not had any problem, but that is not to say it is problem free.
For text documents though I agree with you.
The only real deal-breaker level annoyance I've found with any of the Drive apps so far is that whatever Javascript the writer one is using eats up enough CPU power to drop my Macbook's battery life to about a quarter of what it normally is.
I'm not a power user, but I'd say Google Sheets are good enough for almost all of us. Google Write, not so much.
As a handy collaborative text editor with some basic formatting, it's fine. For longer documents, technical documents, anything that needs professional levels of review and revision control, or basically any other "serious" work, it's not even entry-level.
Likewise if you want to share some tables with light formatting and maybe some simple calculations, the on-line spreadsheets are fine. However, anyone who does significant number crunching using a real spreadsheet isn't going to last five minutes.
In short, if you find the real-time collaboration useful and need only very simple formatting and manipulation, these on-line suites are fine (and of course this probably does cover a fair amount of useful work). If you need anything more sophisticated, they aren't really competing with the heavyweight desktop applications at all.
But then again, I'm the sort of user who runs LO on Linux compiled from git master just because I can ;-)