Create yourself a large bucket that can hold much more water or lava. From now on, you will have at your disposal a huge bucket that can replace several ordinary ones at once.
Big Bucket Mod for Minecraft 1.16.4/1.16.1/1.15.2
Agree that it is much more convenient to carry only one but large bucket with you than many filled small ones. It is extremely convenient and easy to craft.
1.16.4 – Big-Buckets-Mod-1.16.4
1.16.1 – Big-Buckets-Mod-1.16.1
1.15.2 – Big-Buckets-Mod-1.15.2