I've overseen more than 300 HubSpot CRM implementations. If you asked me to name the single biggest reason they fail, I wouldn't point to the software. I'd point to what happens before anyone opens HubSpot at all.
I got into this in detail on a recent episode of the Predictable B2B Success podcast with Vinay Koshy, and I wanted to pull the thread further here because it's a topic I keep coming back to with clients: CRM implementation is a revenue operations project that happens to involve software, not the other way around.
You can listen to the full episode here.