Looking at the training schedule of elite level cyclists, apparently they do this most of the year and do little high-intensity to prep for a race (in terms of percentage training time).
The 20-25 hour a week training schedule? And then the 25-35 hour a week racing schedule? Not particularly useful.
If the OP could ride that many hours, they'd probably be pretty fast, too. For all of us that don't, intensity helps make up for the training load which is instrumental in forcing adaptations (i.e., making you faster).
Riding 5-10 hours a week without much intensity isn't going to make you much faster once you've established some baseline fitness.