As easy as it is to get a domain, and as much content is out there on how to create your first website, the often overlooked aspect is how people are going to notice your website. Social media exposure always does a decent job, but until you've landed organic searches, you're not doing good enough.
Optimisation is always absolutely needed, especially when people believe it's not. Optimisation makes sure your website is seen, your organic searches are high, and that your website is up to date with everything it needs to be.
This isn't only exclusive to plain websites either, this goes for marketplaces as well. You have a Shopify page? You have an Amazon shop? You upload videos on YouTube? Every single one of those requires optimisation as well. Never overlook it and act on time.