This is not realistic. Performance doesn't just happen. Within limited constraints, focusing on performance will necessarily imply less feature.
Ultimately, it's about balance. Personally I find VSC's performance to be good, and at lot of other devs find it at least good enough (it's a widespread editor). I've actually switched away from ST3 because the development of their current version stagnated, and there are unresolved bugs and limitations that affected my everyday usage.
In other words, the performance/features (and let's throw flexibility) balance of VSC is, for me, better than ST's (others may have have different requirements and different balances, of course).
Ultimately, VSC is a bad example of tradeoff performance/ease of (internal) development. If people wants to find an example, Slack is by far the best (worst).