If you begin taking up climbing rides as I did after years of just flat cruising, you'll experience a transition period of somewhat painful muscle building. To suffer the least I used the lowest gear I had, which was the 30/26, or 34/30 combo on two different bikes. After a time, I was able to increase my speed on climbs by using a higher gear without pain, the obvious result of successful muscle building. Climbs that previously required the lowest gear combo were being ridden up using at least two gear ratios higher, so those two remaining low gears on the cassette were relegated to "bail" status. I do still use them from time to time, especially at the end of 50+ miles of riding in the surrounding "semi-mountainous" region where I live. All my local rides beginning from home end with a difficult 1/4 mile slog up a steep hill, which is the perfect time to use the lowest "bail" gear. For that reason, I'll always use a cassette with at least one bail gear, even if it looks like I'm riding around with a pie plate for a cassette.