You've posted repeatedly like this in this thread. That's not allowed in someone else's launch thread (YC company or otherwise)—it's extremely bad manners. Please stop now.
It's maybe ok to post one comment telling people about your alternative product, depending on how you do that. More than that, it starts to be spamming.
Received your cold LinkedIn message... founder to founder, spending time on building a better product is always going to yield better results than scraping your competitor's launch announcement to send cold messages to all their commenters.
If you are going to reach out, I've always found it helpful when a company speaks to their differences and in a positive tone, rather than throwing shade.