In my opinion the bad ergonomics is actually when authoring the components (not consuming it). Many of the faults have been excellently pointed out previously[1]. The most glaring the boilerplate you have to write if you want your attributes to reflect a property.
This has an easy fix though, which is that you simply don’t write your web components by hand. You either use a library (like lit-element[2]) or a compiler (like stencil[3]). I’m personally waiting for a less opinionated compiler with a smaller runtime then stencil (preferably no runtime; perhaps that is Svelte with a web component target, I haven’t tried it).
There is also a proposal for a declarative shadow DOM[4], which aims to tackle some of the bad dev experience we have with web components. However I’m personally a little skeptic that it is a good proposal, or that it will fix what most web component devs are concerned about.
1: https://dev.to/richharris/why-i-don-t-use-web-components-2ci...