This is great feedback to help optimize the site but I wouldn’t lose sleep over it u til you’ve proven the concept. As an early iteration I’m glad you made a useful tool and you shipped it. Optimizing bundle sizes is much easier than making something useful.

That being said, getting feedback like this helps you spot ways to make it better. I’m on an iPhone X with very good data most of the time so my opinion is going to be biased toward not caring about 1MB of js that will be cached in future visits.