Slow pages lose demos before the headline loads, and Google measures the delay. But most performance problems on B2B websites are not technical. They are editorial: A 4 MB hero image, five tracking scripts and a video that autoplays on a phone.
The good news is that marketing can fix most of it.
A slower page converts worse, ranks worse and gets crawled less, including by the AI engines now reading your site. Speed is not a developer concern. It is part of the offer.
Google's three numbers, in plain language:
HubSpot serves your site from a global CDN, resizes images on the fly and minifies the theme's CSS and JavaScript. Omni is built from HubSpot's own building blocks, so there is no plugin stack adding weight, and every module is responsive by default with no separate mobile layouts to maintain.
That covers the platform. It does not cover what you upload.
Run your home page and your busiest landing page through PageSpeed Insights. Open the Core Web Vitals report in Google Search Console. Fix the worst page first, then repeat once a month. Use Omni's mobile preview before you publish; that is where most of the layout shifting shows up.