There you have it. Using bleeding edge features will create a lot of problems. First you need to figure out what type of users you want to target, PC users with 24 inch monitors and keyboard? Or 12 year olds with iPads? But still, for your software to really work across as many units as possible, and continue to work for years, you have to look what existed 5-10 years ago, and only use those features that are still standard.
I have a mobile phone that no longer gets updates. It is HTML 5 compatible, so it should handle everything that is not bleeding edge, but still many web pages, for example medium.com does not work!
I remember being a web developer ten years ago, it was your professional duty do make sure it was pixel perfect on existing GUI based browsers and even look good on the text based ones. I think web dev's today is too quick to jump on the latest and greatest.
If you take a look at the browser features that existed 5-10 years ago, it's way behind the native phone app experience! It seems browser vendors totally missed the mobile explosion, and only lately have begun to catch up! Considering how fast the web tech moves now though, the future for web dev looks bright. I think that in in 5-10 years, the mobile browser experience will be on pair or even ahead of native, at least considering dev experience and cross device/platform support.