By default Next.js scores 100/100 on performance and best practices eg https://nextjs-3q3i4heaj.now.sh/ (SEO / Accessibility are not 100 as I didn't add meta tags in this example, but are very trivial to add.)

In case of Invision it seems like images / render blocking css that was added outside of Next.js are the main culprit. I've reached out to Jon Wheeler who works on the marketing site to make him aware.