There are no dry spots in the Bible. It's all (including genealogies) there for a reason that the Lord is able to teach is something about Himself.
But let's face it. There are times when this doesn't ring true in our lives. We read certain sections of the Bible, and we are not hearing the Lord speak through it. Much of this has to do with our heart's preparedness for it, but maybe there's a thing we can do to keep the time with Good more fruitful in our mind.
If you were in a relationship, where you were starting to get a bit uninterested and disengaged in your conversations, you would try to change things up for a while within that relationship.
Now, God is not your boy/girlfriend, but there can ring a statement of truth that we should try to maybe change things up a bit if we're coming across a dry spot in our daily devotions. So if you're reading through Isaiah and seem lost as to what's going on, perhaps it would be good to take a break for a while to read through the story of Joseph.
And maybe when you read through Joseph and return to the book of Isaiah, your heart will be more prepared to hear what the Lord has for you.
But maybe that's not the best choice for your life specifically. What I do think is true though is that we shouldn't just sit back and do nothing if we start to find our daily devotions becoming unfruitful in nature.