I never have any problems with YouTube; it works well for me. What problems are there? I use Google Docs only sporadically (mostly to read .doc(x) files sent to me), and it's kinda slow, but that's not necessarily Google's fault. Slack is (was? Haven't used it in year) unusably slow on Firefox too, and don't get me started on the "new" Reddit that couldn't even scroll right last time I tried it.