Fingers crossed yeah. CM is not terrible, it just kind of exists as a by the numbers origin story. The problem with that is we saw better ones over 10 years ago so it can be a bit tedious in that respect. Don't panic you need to see Marvel before End Game though as it will not ruin continuity if you wait for the bluray etc of that.
3hrs, damn. I suppose they have a lot to get through though. I would rather a movie take the time it really needs as opposed to the DCEU who demand it no longer than 150mins which i find a terrible policy for good movie making. Infinity war was a feast of movie, so much movie in that movie, it was just bursting with movie. Some would even say if not rushed the story in it had 0 excess, every frame of the film was important to the plot.
On a side note-ish, i have just watched the trailer 10 times. I need help!