I use it daily for years and was shocked to find that it supports pinch zoom on iOS - but not android (where i use it).
Feels like it that's just tip of the iceberg re. things they could improve - for example they finally, finally!, added ability to create categories/tags for free (was paid feature).
I understand it's tough to run a business like this (and why google killed this, at least officially) - but i wouldn't actually mind an occasional ad.
However i wouldn't consider it for mission critical stuff - github's infrastructure can't be compared to actual paid-for cloud hosting.