These wheels won't be reliable if the user rides often when its raining or when the roads are wet, even worse on dirt road: the bearings have no protection at all against water and dirt entering in them and with such a small diameter they receive much more water and dirt than usual bicycle wheels.

So called waterproof bearings are actually not waterproof, they just have a little better protection.

And most bearings are not rustproof, so when water enter, they rust what destroy them very quickly (there are stainless steel bearings and ceramic bearing but they are not common and expensive).

The problem of water and dirt entering the bearings is a very well known problem of kick scooters and also inline skates (who have now much bigger diameter wheels than in the past).