Construct supports Javascript coding in addition to its block-based approach. Javascript is an industry-standard language used widely across browsers, servers a...
Many of us who use Construct do it because we don't know how to program in traditional way.
Now, how would Javascript blocks compare with if you ran exact same thing but constructed through events. This is probably the way most would use Construct for.
One thing to consider -
If you worked for years on a project and found a bottleneck with your event blocks, you have a possible option to try and implement javascript with any of the more cpu-heavy parts of your event blocks. Sure, most will think "uhh but I don't know javascript" BUT, you are not stuck at a dead-end, you could ask community members or post on the forums explaining what you're trying to do, and some javascript god might end up offering suggestions or a path to go down in order to achieve what you want.
It may be that not a lot of people will not utilise this, but if someone finds themselves needing to eek out some more performance somewhere for their huge complex multi-system RPG project, then it's amazing we have the option to go to the core and try to gain even more performance.
The blog post includes both a JavaScript and event block based version of the performance benchmark. You can try them both out yourself.