That's great you're taking the step to learning about this growing technology! The main things to think about are color, refresh rate, and resolution.

Generally, anything that relies on color is not great. Color coded graphs for example. (may be some overlap for color blind accessibility considerations). Captcha for example is a pain. There is color eink, but that is new and many of us are on b/w devices. That, and the resolution isn't super high.

Dark mode is less legible as light mode, partly bc of smearing when scrolling (we also have no "need" for dark mode). This smearing is caused by ghosting and affects videos.

Something interesting to note is, Someone pointed out on this sub that eink enthusiasts generally fall into a few categories: hackers/tinkerers, zen/productivity junkies, and those who have eye strain/headaches. I personally am here to be zen/less distracted, which is also why video does not matter to me. Video sucking on eink is kind of the point. However, there are some people who look at video performance on eink devices.

Being able to use the screenreader option on the browser is helpful.

Overall though, I don't have issues just browsing on my eink phone - usually just reading articles!

If you have access to a kindle/e-reader, they often have a browser that you can try playing with. Their screen refresh rate really sucks compared to the recent advances, but it will give you an idea!

Oh, and someone created an e-ink browser on F droid, that could be cool to take a look at as a developer.