I feel that nothing significant has changed over the past decade. There newer frameworks that are faster not in order of magnitudes, more stable, have a bit mor

I feel that nothing significant has changed over the past decade. There newer frameworks that are faster not in order of magnitudes, more stable, have a bit more features or run in the browser itself but at the end you are interacting with elements in your DOM and you are dependent on 20 other cogs and gears that are not part of the browser. Your best bet would be doing automated smoke GUI testing, lots of API testing and below and above all a layer of manual testing done by the whole team during and after development. In one team we used high speed cameras, or screen captures on mobiles, to capture images containing debug timestamps and do image comparison of selected regions to reference ones, I think it was using imagemagick. This worked but required constant maintenance and manual interventions.