I am pretty happy with the water cans from Tractor Supply. I had one for three years until I lost the screen for the spout and that seriously reduced the usefulness. So this year I bought two more and marked them for front and back yard. This year's are bright green instead of a more stately green, but whatever. Still the same size and config, for the most part, a centered fill hole and over 2 gal capacity.

I modify the screens a little by drilling out some of the holes a little larger. This allows a faster pour. The screen should be drilled from the inside, so the plastic wells up to the outside, better flow this way.

I use water barrels from roof rain. One issue with dunking a watering can in there is that there will be grit, bio dirt, leaves, maple spinners, etc that will get ingested during the fill and then trapped against the screen. A mesh basket from $1.25tree is a cheap solution. It gets zip tied to the handle. This allows it to be wedged in place to dunk and fill but also easy to pop out to pour back out the fill hole to fill the birdbath.

This bright green version of the watering can has a different friction ring design for the spout. I had some trouble with not coming off, too tight. So I sanded the ring, or something, and then it would not stay on, too loose. So I drilled and pinned it instead, and like it a lot better. I do not like to take the screen off the spout if I can help it - it is just plastic tabs retaining the screen and will eventually break. This just works better, and a 1/4-20 nut and bolt would work as well as the ladder stand pin.

We have a similar setup at the farm with 2+gal cans that get filled in the rainbarrel. I never noticed much leaves and etc. in the barrel, but then again the spouts on those are simpler than yours, seems more like a single piece of molded plastic, perhaps? Industrial strength for sure, because the crappy ones I end up with in my garden always always get the spout knocked off.