I "bought" a lot of speed & endurance for $60 going to cheap 28mm tires & tubes on my hybrid.
I've since built a set of "skinny" wheels and went to 25mm tires which gave me more endurance.

The 2nd thing is GEARING!
Chances are you likely have an 11-3X cassette.
You probably find the 11T cog useless and possibly the 3XT cog not needed.
Get a 12/13T small cog cassette with the largest cog no bigger than needed.
Maybe something like a 12/13-25/26T?
That will give you more closely spaced gears which will allow you to maintain a cadence that works best for you.

BTW- IF your seat height is too low, that can sap a lot of energy.