Why do websites that use HubSpot seem to always have many SEO problems?

Could you qualify that a bit? Hundreds of thousands of websites “use HubSpot” and many of them perform extremely well from an SEO perspective.

Do you mean host on HubSpot? Or simply use the marketing automation tools? In either case, I’ve been working with HubSpot for years and seen the opposite of what you’re describing.

I’d love to see some data backing up your claim.